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40 >AFS Administration Guide: Version 3.6</TH
77 >Chapter 7. Backing Up and Restoring AFS Data</H1
79 >The instructions in this chapter explain how to back up and restore AFS data and to administer the Backup Database. They
80 assume that you have already configured all of the Backup System components by following the instructions in <A
82 >Configuring the AFS Backup System</A
90 >Summary of Instructions</A
93 >This chapter explains how to perform the following tasks by using the indicated commands:</P
108 >Enter interactive mode</TD
114 >backup (interactive)</B
120 >Leave interactive mode</TD
132 >List operations in interactive mode</TD
144 >Cancel operation in interactive mode</TD
156 >Start Tape Coordinator</TD
168 >Stop Tape Coordinator</TD
180 >Check status of Tape Coordinator</TD
204 >Display dump records</TD
216 >Display volume's dump history</TD
228 >Scan contents of tape</TD
246 >backup volrestore</B
252 >Restore partition</TD
258 >backup diskrestore</B
264 >Restore group of volumes</TD
270 >backup volsetrestore</B
276 >Verify integrity of Backup Database</TD
288 >Repair corruption in Backup Database</TD
306 >Delete dump set from Backup Database</TD
312 >backup deletedump</B
326 >Using the Backup System's Interfaces</A
329 >When performing backup operations, you interact with three Backup System components: <UL
332 >You initiate backup operations by issuing commands from the <SPAN
339 issue the commands in a command shell (or invoke them in a shell script) on any AFS client or server machine from which
340 you can access the <SPAN
346 > binary. In the conventional configuration, the binary resides
353 > directory on a server machine and the <SPAN
359 > directory on a client machine.</P
361 >The suite provides an <SPAN
367 >, in which you can issue multiple commands over a
368 persistent connection to the Backup Server and the Volume Location (VL) Server. Interactive mode has several convenient
369 features. For a discussion and instructions, see <A
370 HREF="c15383.html#HDRWQ288"
371 >Using Interactive and Regular Command
375 >Note that some operating systems include a <SPAN
381 > command of their own. You must
382 configure machines that run such an operating system to ensure that you are accessing the desired <SPAN
392 >Before you perform a backup operation that involves reading or writing to a tape device or backup data file, you
393 must open a dedicated connection to the appropriate Tape Coordinator machine and start the Tape Coordinator (<SPAN
399 >) process that handles the device or file. The <SPAN
406 must continue to run over the dedicated connection as long as it is executing an operation or is to be available to
407 execute one. For further discussion and instructions, see <A
408 HREF="c15383.html#HDRWQ291"
409 >Starting and Stopping the Tape
410 Coordinator Process</A
415 >The Backup Server (<SPAN
421 >) process must be running on database server machines,
422 because most backup operations require accessing or changing information in the Backup Database. The <SPAN
429 > explains how to configure the Backup Server.</P
434 >For consistent Backup System performance, the AFS build level of all three binaries (<SPAN
453 For instructions on displaying the build level, see <A
454 HREF="c3025.html#HDRWQ117"
455 >Displaying A Binary File's Build
464 >Performing Backup Operations as the Local Superuser Root or in a Foreign Cell</A
467 >By default, the volumes and Backup Database involved in a backup operation must reside on server machines that belong to
468 the cell named in the <SPAN
472 >/usr/vice/etc/ThisCell</B
474 > files on both the Tape Coordinator machine and
475 the machine where you issue the <SPAN
481 > command. Also, to issue most <SPAN
487 > commands you must have AFS tokens for an identity listed in the local cell's <SPAN
491 >/usr/afs/etc/UserList</B
493 > file (which by convention is the same on every server machine in a cell). You
494 can, however, perform backup operations on volumes or the Backup Database from a foreign cell, or perform backup operations
495 while logged in as the local superuser <SPAN
501 > rather than as a privileged AFS identity.</P
503 >To perform backup operations on volumes that reside in a foreign cell using machines from the local cell, you must
504 designate the foreign cell as the cell of execution for both the Tape Coordinator and the <SPAN
510 > command interpreter. Use one of the two following methods. For either method, you must also have
511 tokens as an administrator listed in the foreign cell's <SPAN
515 >/usr/afs/etc/UserList</B
521 >Before issuing <SPAN
527 > commands and the <SPAN
534 command, set the AFSCELL environment variable to the foreign cell name in both command shells.</P
544 > argument to the <SPAN
557 > commands. If you include the argument on the <SPAN
564 > command, it applies to all commands issued during the interactive session.</P
569 >To perform backup operations without having administrative AFS tokens, you must log on as the local superuser <SPAN
575 > on both the Tape Coordinator machine and the machine where you issue <SPAN
581 > commands. Both machines must be server machines, or at least have a <SPAN
585 >/usr/afs/etc/KeyFile</B
587 > file that matches the file on other server machines. Then include the <SPAN
593 > argument on both the <SPAN
599 > command and all <SPAN
605 > commands (or the <SPAN
609 >backup (interactive)</B
612 Coordinator and <SPAN
618 > command interpreter construct a server ticket using the server
619 encryption key with the highest key version number in the local <SPAN
623 >/usr/afs/etc/KeyFile</B
626 and present it to the Backup Server, Volume Server, and VL Server that belong to the cell named in the local <SPAN
630 >/usr/afs/etc/ThisCell</B
632 > file. The ticket never expires.</P
634 >You cannot combine the <SPAN
647 the same command. Also, each one overrides the local cell setting defined by the AFSCELL environment variable or the <SPAN
651 >/usr/vice/etc/ThisCell</B
661 >Using Interactive and Regular Command Mode</A
670 > command suite provides an interactive mode, in which you can issue multiple
671 commands over a persistent connection to the Backup Server and the VL Server. Interactive mode provides the following
676 CLASS="computeroutput"
678 > prompt replaces the usual command shell prompt.</P
682 >You omit the initial <SPAN
688 > string from command names. Type only the operation
689 code and option names.</P
693 >You cannot issue commands that do not belong to the <SPAN
703 >If you assume an administrative AFS identity or specify a foreign cell as you enter interactive mode, it applies
704 to all commands issued during the interactive session. See <A
705 HREF="c15383.html#HDRWQ287"
706 >Performing Backup Operations as the
707 Local Superuser Root or in a Foreign Cell</A
712 >You do not need to enclose shell metacharacters in double quotes.</P
717 >When you initiate a backup operation in interactive mode, the Backup System assigns it a <SPAN
724 >. You can display the list of current and pending operations with the <SPAN
731 > command, for which instructions appear in <A
732 HREF="c15383.html#HDRWQ289"
733 >To display pending or running jobs in
735 >. (In both regular and interactive modes, the Tape Coordinator also assigns a <SPAN
742 > to each operation you initiate with a <SPAN
748 > command. You can track task ID
749 numbers with the <SPAN
756 HREF="c15383.html#HDRWQ291"
757 >Starting and Stopping
758 the Tape Coordinator Process</A
761 >You can cancel an operation in interactive mode with the <SPAN
768 which instructions appear in <A
769 HREF="c15383.html#HDRWQ290"
770 >To cancel operations in interactive mode</A
771 >. However, it is best not
772 to interrupt a dump operation because the resulting dump is incomplete, and interrupting a restore operation can leave volumes
773 in an inconsistent state, or even completely remove them from the server machine. For further discussion, see <A
774 HREF="c15383.html#HDRWQ296"
777 HREF="c15383.html#HDRWQ306"
778 >Restoring and Recovering Data</A
794 available only in interactive mode and there is no equivalent functionality in regular command mode.</P
802 >To enter interactive mode</A
808 >Verify that you are authenticated as a user listed in the <SPAN
812 >/usr/afs/etc/UserList</B
815 file. Entering interactive mode does not itself require privilege, but most other <SPAN
822 commands do, and the AFS identity you assume when entering the mode applies to all commands you issue within it. If
823 necessary, issue the <SPAN
829 > command, which is fully described in <A
830 HREF="c32432.html#HDRWQ593"
831 >To display the users in the UserList file</A
833 CLASS="programlisting"
856 >backup (interactive)</B
858 > command at the system prompt. The
860 CLASS="computeroutput"
862 > prompt appears. You can include either, but not both, of the <SPAN
874 > options, as discussed in <A
875 HREF="c15383.html#HDRWQ287"
876 >Performing Backup Operations as the Local Superuser Root or in a Foreign Cell</A
878 CLASS="programlisting"
898 >To exit interactive mode</A
910 > command at the <SAMP
911 CLASS="computeroutput"
914 The command shell prompt reappears when the command succeeds, which it does only if there are no jobs pending or currently
915 running. To display and cancel pending or running jobs, follow the instructions in <A
916 HREF="c15383.html#HDRWQ289"
918 pending or running jobs in interactive mode</A
920 HREF="c15383.html#HDRWQ290"
921 >To cancel operations in interactive
924 CLASS="programlisting"
925 > backup> <SPAN
944 >To display pending or running jobs in interactive mode</A
956 > command at the <SAMP
957 CLASS="computeroutput"
961 CLASS="programlisting"
962 > backup> <SPAN
985 >Is the shortest acceptable abbreviation of <SPAN
999 >The output always includes the expiration date and time of the tokens that the <SPAN
1006 command interpreter is using during the current interactive session, in the following format:</P
1008 CLASS="programlisting"
1009 > date time: TOKEN EXPIRATION
1012 >If the execution date and time specified for a scheduled dump operation is later than <SPAN
1019 then its individual line (as described in the following paragraphs) appears below this line to indicate that the current
1020 tokens will not be available to it.</P
1022 >If the issuer of the <SPAN
1028 > command included the <SPAN
1034 > flag when entering interactive mode, the line instead reads as follows:</P
1036 CLASS="programlisting"
1037 > : TOKEN NEVER EXPIRES
1040 >The entry for a scheduled dump operation has the following format:</P
1042 CLASS="programlisting"
1043 > Job job_ID: timestamp: dump volume_set dump_level
1047 CLASS="variablelist"
1059 >Is a job identification number assigned by the Backup System.</P
1071 >Indicates the date and time the dump operation is to begin, in the format month/date/year hours:minutes (in
1084 >Indicates the volume set to dump.</P
1096 >Indicates the dump level at which to perform the dump operation.</P
1102 >The line for a pending or running operation of any other type has the following format:</P
1104 CLASS="programlisting"
1105 > Job job_ID: operation status
1109 CLASS="variablelist"
1121 >Is a job identification number assigned by the Backup System.</P
1133 >Identifies the operation the Tape Coordinator is performing, which is initiated by the indicated command:
1135 CLASS="variablelist"
1143 CLASS="computeroutput"
1150 >Initiated by the <SPAN
1156 > command. The dump name has the following
1159 >volume_set_name<SPAN
1173 CLASS="computeroutput"
1180 >Initiated by the <SPAN
1184 >backup diskrestore</B
1197 >backup volsetrestore</B
1207 CLASS="computeroutput"
1214 >Initiated by the <SPAN
1218 >backup labeltape</B
1220 > command. The tape_label is the name
1221 specified by the <SPAN
1225 >backup labeltape</B
1247 CLASS="computeroutput"
1254 >Initiated by the <SPAN
1268 CLASS="computeroutput"
1275 >Initiated by the <SPAN
1289 CLASS="computeroutput"
1296 >Initiated by the <SPAN
1300 >backup restoredb</B
1318 >Indicates the job's current status in one of the following messages. If no message appears, the job is either
1319 still pending or has finished. <DIV
1320 CLASS="variablelist"
1328 CLASS="computeroutput"
1329 >Kbytes, volume volume_name</SAMP
1335 >For a running dump operation, indicates the number of kilobytes copied to tape or a backup data file so
1336 far, and the volume currently being dumped.</P
1344 CLASS="computeroutput"
1345 >Kbytes, restore.volume</SAMP
1351 >For a running restore operation, indicates the number of kilobytes copied into AFS from a tape or a
1352 backup data file so far.</P
1360 CLASS="computeroutput"
1361 >[abort requested]</SAMP
1373 > command was issued, but the termination signal has
1374 yet to reach the Tape Coordinator.</P
1382 CLASS="computeroutput"
1389 >The operation is canceled by the <SPAN
1395 > command. Once the Backup
1396 System removes an operation from the queue or stops it from running, it no longer appears at all in the output
1397 from the command.</P
1405 CLASS="computeroutput"
1406 >[butc contact lost]</SAMP
1418 > command interpreter cannot reach the Tape Coordinator. The
1419 message can mean either that the Tape Coordinator handling the operation was terminated or failed while the
1420 operation was running, or that the connection to the Tape Coordinator timed out.</P
1428 CLASS="computeroutput"
1435 >The Tape Coordinator has finished the operation.</P
1443 CLASS="computeroutput"
1450 >The operation is waiting for the specified tape drive to become free.</P
1458 CLASS="computeroutput"
1459 >[operator wait]</SAMP
1465 >The Tape Coordinator is waiting for the backup operator to insert a tape in the drive.</P
1481 >To cancel operations in interactive mode</A
1493 > command at the <SAMP
1494 CLASS="computeroutput"
1497 to learn the job ID number of the operation you want to cancel. For details, see <A
1498 HREF="c15383.html#HDRWQ289"
1500 pending or running jobs in interactive mode</A
1502 CLASS="programlisting"
1503 > backup> <SPAN
1521 > command to cancel the operation. <PRE
1522 CLASS="programlisting"
1523 > backup> <SPAN
1533 >job ID or dump set name</I
1540 CLASS="variablelist"
1552 >Is the shortest acceptable abbreviation of <SPAN
1565 >job ID or dump set name</B
1570 >Specifies either the job ID number of the operation to cancel, as reported by the <SPAN
1576 > command, or for a dump operation only, the dump name in the format
1577 volume_set_name.dump_level_name.</P
1591 >Starting and Stopping the Tape Coordinator Process</A
1594 >Before performing a backup operation that reads from or writes to a tape device or backup data file, you must start the
1595 Tape Coordinator (<SPAN
1601 >) process that handles the drive or file. This section explains how to
1602 start, stop, and check the status of a Tape Coordinator process. To use these instructions, you must have already configured
1603 the Tape Coordinator machine and created a Tape Coordinator entry in the Backup Database, as instructed in <A
1604 HREF="c12776.html#HDRWQ261"
1605 >Configuring Tape Coordinator Machines and Tape Devices</A
1608 >The Tape Coordinator assigns a <SPAN
1614 > to each operation it performs. The number is distinct
1615 from the job ID number assigned by the <SPAN
1621 > command interpreter in interactive mode (which
1623 HREF="c15383.html#HDRWQ288"
1624 >Using Interactive and Regular Command Mode</A
1625 >). The Tape Coordinator reports the
1626 task ID number in its onscreen trace and in the messages that it writes to its log and error files. To view the task ID
1627 numbers of a Tape Coordinator's running or pending operations, issue the <SPAN
1642 >To start a Tape Coordinator process</A
1648 >Verify that you are authenticated as a user listed in the <SPAN
1652 >/usr/afs/etc/UserList</B
1655 file of the cell in which the Tape Coordinator is to access volume data and the Backup Database. If necessary, issue the
1662 > command, which is fully described in <A
1663 HREF="c32432.html#HDRWQ593"
1665 the users in the UserList file</A
1667 CLASS="programlisting"
1684 >Alternately, you can log into a file server machine as the local superuser <SPAN
1692 HREF="c15383.html#LIWQ293"
1698 >Verify that you can write to the Tape Coordinator's log and error files in the local <SPAN
1704 > directory (the <SPAN
1710 >device_name and <SPAN
1716 >device_name files). If the log and error files do not already exist, you must be able to insert
1717 and write to files in the <SPAN
1730 >Open a connection (using a command such as <SPAN
1743 >) to the Tape Coordinator machine that drives the tape device, or whose local disk
1744 houses the backup data file. The Tape Coordinator uses a devoted connection or window that must remain open for the Tape
1745 Coordinator to accept requests and while it is executing them.</P
1747 >If you plan to include the <SPAN
1759 > command in the next step, log in as the local superuser <SPAN
1778 > command to start the Tape Coordinator. You
1779 can include either, but not both, of the <SPAN
1791 > options, as discussed in <A
1792 HREF="c15383.html#HDRWQ287"
1793 >Performing Backup Operations as the Local
1794 Superuser Root or in a Foreign Cell</A
1796 CLASS="programlisting"
1851 CLASS="variablelist"
1863 >Must be typed in full.</P
1875 >Specifies the Tape Coordinator's port offset number. You must provide this argument unless the default value
1882 > (zero) is appropriate.</P
1894 >Specifies the type of trace messages that the Tape Coordinator writes to the standard output stream
1895 (stdout). Provide one of the following three values, or omit this argument to display the default type of messages
1896 (equivalent to setting a value of <SPAN
1911 >: The Tape Coordinator generates only the minimum number of messages
1912 necessary to communicate with the backup operator, including prompts for insertion of additional tapes and
1913 messages that indicate errors or the beginning or completion of operations.</P
1923 >: In addition to the messages displayed at level <SPAN
1929 >, the Tape Coordinator displays the name of each volume being dumped or
1940 >: In addition to the messages displayed at levels <SPAN
1952 >, the Tape Coordinator displays all of the
1953 messages it is also writing to its log file (<SPAN
1957 >/usr/afs/backup/TL_</B
1974 >Names the cell in which to perform the backup operations (the cell where the relevant volumes reside and the
1975 Backup Server process is running). If you omit this argument, the Tape Coordinator uses its home cell, as defined
1980 >/usr/vice/etc/ThisCell</B
1982 > file. Do not combine this argument with the
2001 >Disables the Tape Coordinator's prompt for the first tape it needs for each operation. For a description of
2002 the advantages and consequences of including this flag, see <A
2003 HREF="c12776.html#HDRWQ278"
2004 >Eliminating the Search or
2005 Prompt for the Initial Tape</A
2018 >Constructs a server ticket using a key from the local <SPAN
2022 >/usr/afs/etc/KeyFile</B
2031 > process presents it to the Backup Server, Volume Server, and VL
2032 Server during mutual authentication. You must be logged into a file server machine as the local superuser
2039 > to include this flag, and cannot combine it with the <SPAN
2059 >To stop a Tape Coordinator process</A
2065 >Enter an interrupt signal such as <<SPAN
2071 >> over the dedicated connection to
2072 the Tape Coordinator.</P
2082 >To check the status of a Tape Coordinator process</A
2088 >Verify that you are authenticated as a user listed in the <SPAN
2092 >/usr/afs/etc/UserList</B
2095 file. If necessary, issue the <SPAN
2101 > command, which is fully described in <A
2102 HREF="c32432.html#HDRWQ593"
2103 >To display the users in the UserList file</A
2105 CLASS="programlisting"
2131 CLASS="programlisting"
2149 CLASS="variablelist"
2161 >Is the shortest acceptable abbreviation of <SPAN
2179 >Specifies the Tape Coordinator's port offset number. You must provide this argument unless the default value
2186 > (zero) is appropriate.</P
2194 >The following message indicates that the Tape Coordinator is not currently performing an operation:</P
2196 CLASS="programlisting"
2197 > Tape coordinator is idle
2200 >Otherwise, the output includes a message of the following format for each running or pending operation:</P
2202 CLASS="programlisting"
2203 > Task task_ID: operation: status
2207 CLASS="variablelist"
2219 >Is a task identification number assigned by the Tape Coordinator. It begins with the Tape Coordinator's port
2232 >Identifies the operation the Tape Coordinator is performing, which is initiated by the indicated command:
2237 CLASS="computeroutput"
2250 CLASS="computeroutput"
2256 >backup diskrestore</B
2263 >backup volrestore</B
2269 >backup volsetrestore</B
2277 CLASS="computeroutput"
2283 >backup labeltape</B
2291 CLASS="computeroutput"
2305 CLASS="computeroutput"
2319 CLASS="computeroutput"
2325 >backup restoredb</B
2343 >Indicates the job's current status in one of the following messages. <DIV
2344 CLASS="variablelist"
2352 CLASS="computeroutput"
2353 >Kbytes transferred, volume</SAMP
2360 >For a running dump operation, indicates the number of kilobytes copied to tape or a backup data file so
2361 far, and the volume currently being dumped.</P
2369 CLASS="computeroutput"
2370 >Kbytes, restore.volume</SAMP
2376 >For a running restore operation, indicates the number of kilobytes copied into AFS from a tape or a
2377 backup data file so far.</P
2385 CLASS="computeroutput"
2386 >[abort requested]</SAMP
2398 > command was issued, but the termination signal has
2399 yet to reach the Tape Coordinator.</P
2407 CLASS="computeroutput"
2414 >The operation is canceled by the <SPAN
2420 > command. Once the Backup
2421 System removes an operation from the queue or stops it from running, it no longer appears at all in the output
2422 from the command.</P
2430 CLASS="computeroutput"
2431 >[butc contact lost]</SAMP
2443 > command interpreter cannot reach the Tape Coordinator. The
2444 message can mean either that the Tape Coordinator handling the operation was terminated or failed while the
2445 operation was running, or that the connection to the Tape Coordinator timed out.</P
2453 CLASS="computeroutput"
2460 >The Tape Coordinator has finished the operation.</P
2468 CLASS="computeroutput"
2475 >The operation is waiting for the specified tape drive to become free.</P
2483 CLASS="computeroutput"
2484 >[operator wait]</SAMP
2490 >The Tape Coordinator is waiting for the backup operator to insert a tape in the drive.</P
2500 >If the Tape Coordinator is communicating with an XBSA server (a third-party backup utility that implements the Open
2501 Group's Backup Service API [XBSA]), the following message appears last in the output:</P
2503 CLASS="programlisting"
2504 > XBSA_program Tape coordinator
2507 >where XBSA_program is the name of the XBSA-compliant program.</P
2519 >This section explains how to use the <SPAN
2525 > command to back up AFS data to tape or
2526 to a backup data file. The instructions assume that you understand Backup System concepts and have already configured the Backup
2527 System according to the instructions in <A
2529 >Configuring the AFS Backup System</A
2530 >. Specifically, you
2531 must already have: <UL
2534 >Decided whether to dump data to tape or to a backup data file, and configured the Tape Coordinator machine and Tape
2535 Coordinator process appropriately. See <A
2536 HREF="c12776.html#HDRWQ261"
2537 >Configuring Tape Coordinator Machines and Tape
2540 HREF="c12776.html#HDRWQ282"
2541 >Dumping Data to a Backup Data File</A
2546 >Defined a volume set that includes the volumes you want to dump together. See <A
2547 HREF="c12776.html#HDRWQ265"
2549 Displaying Volume Sets and Volume Entries</A
2554 >Defined the dump level in the dump hierarchy at which you want to dump the volume set. If it is an incremental dump
2555 level, you must have previously created a dump at its parent level. See <A
2556 HREF="c12776.html#HDRWQ267"
2557 >Defining and Displaying
2558 the Dump Hierarchy</A
2563 >Created a device configuration file. Such a file is required for each tape stacker, jukebox device, or backup data
2564 file. You can also use it to configure the Backup System's automation features. See <A
2565 HREF="c12776.html#HDRWQ275"
2567 and Increasing the Efficiency of the Backup Process</A
2573 >The most basic way to perform a dump operation is to create an initial dump of a single volume set as soon as the
2574 appropriate Tape Coordinator is available, by providing only the required arguments to the <SPAN
2581 > command. Instructions appear in <A
2582 HREF="c15383.html#HDRWQ301"
2583 >To create a dump</A
2584 >. The command has several
2585 optional arguments that you can use to increase the efficiency and flexibility of your backup procedures: <UL
2588 >To append a dump to the end of a set of tapes that already contains other dumps, include the <SPAN
2594 > argument. Otherwise, the Backup System creates an initial dump. Appending dumps enables you
2595 to use a tape's full capacity and has other potentially useful features. For a discussion, see <A
2596 HREF="c15383.html#HDRWQ299"
2597 >Appending Dumps to an Existing Dump Set</A
2602 >To schedule one or more dump operations to run at a future time, include the <SPAN
2609 argument. For a discussion and instructions, see <A
2610 HREF="c15383.html#HDRWQ300"
2611 >Scheduling Dumps</A
2616 >To initiate a number of dump operations with a single <SPAN
2629 > argument to name a file in which you have listed the commands. For a discussion
2630 and instructions, see <A
2631 HREF="c15383.html#HDRWQ299"
2632 >Appending Dumps to an Existing Dump Set</A
2634 HREF="c15383.html#HDRWQ300"
2635 >Scheduling Dumps</A
2640 >To generate a list of the volumes to be included in a dump, without actually dumping them, combine the <SPAN
2646 > flag with the other arguments to be used on the actual command.</P
2656 >Making Backup Operations More Efficient</A
2659 >There are several ways to make dump operations more efficient, less prone to error, and less disruptive to your users.
2660 Several of them also simplify the process of restoring data if that becomes necessary. <UL
2663 >It is best not to dump the read/write or read-only version of a volume, because no other users or processes can
2664 access a volume while it is being dumped. Instead, shortly before the dump operation begins, create a backup version of
2665 each volume to be dumped, and dump the backup version. Creating a Backup version usually makes the source volume
2666 unavailable for just a few moments (during which access attempts by other processes are blocked but do not fail). To
2667 automate the creation of backup volumes, you can create a <SPAN
2673 > process in the <SPAN
2677 >/usr/afs/local/BosConfig</B
2679 > file on one or more server machines, setting its start time at a
2680 sufficient interval before the dump operation is to begin. Include the <SPAN
2687 argument to the <SPAN
2700 enable it to run without administrative tokens. For instructions, see <A
2701 HREF="c6449.html#HDRWQ162"
2702 >To create and start a new
2708 >The volume set, dump level, and Tape Coordinator port offset you specify on the <SPAN
2715 > command line must be properly defined in the Backup Database. The Backup System checks the database
2716 before beginning a dump operation and halts the command immediately if any of the required entities are missing. If
2717 necessary, use the indicated commands: <UL
2720 >To display volume sets, use the <SPAN
2724 >backup listvolsets</B
2726 > command as described in
2728 HREF="c12776.html#HDRWQ266"
2729 >To display volume sets and volume entries</A
2734 >To display dump levels, use the <SPAN
2738 >backup listdumps</B
2740 > command as described in
2742 HREF="c12776.html#HDRWQ271"
2743 >To display the dump hierarchy</A
2748 >To display port offsets, use the <SPAN
2752 >backup listhosts</B
2754 > command as described in
2756 HREF="c12776.html#HDRWQ264"
2757 >To display the list of configured Tape Coordinators</A
2765 >Ensure that a valid token corresponding to a privileged administrative identity is available to the Backup System
2766 processes both when the <SPAN
2772 > command is issued and when the dump operation
2773 actually runs (for a complete description or the necessary privileges, see <A
2774 HREF="c12776.html#HDRWQ260"
2776 Administrative Privilege to Backup Operators</A
2777 >). This is a special concern for scheduled dumps. One alternative is
2784 > commands (or the script that invokes them) and the <SPAN
2790 > command on server machines, and to include the <SPAN
2797 argument on the command. In this case, the processes use the key with the highest key version number in the local
2802 >/usr/afs/etc/KeyFile</B
2804 > file to construct a token that never expires. Otherwise, you must
2805 use a method to renew tokens before they expire, or grant tokens with long lifetimes. In either case, you must protect
2806 against improper access to the tokens by securing the machines both physically and against unauthorized network access.
2807 The protection possibly needs to be even stronger than when a human operator is present during the operations.</P
2811 >Record tape capacity and filemark size values that are as accurate as possible in the Tape Coordinator's <SPAN
2815 >/usr/afs/backup/tapeconfig</B
2817 > file and on the tape's label. For suggested values and a description
2818 of what can happen when they are inaccurate, see <A
2819 HREF="c12776.html#HDRWQ258"
2820 >Configuring the tapeconfig File</A
2825 >If an unattended dump requires multiple tapes, arrange to provide them by properly configuring a tape stacker or
2826 jukebox and writing a tape-mounting script to be invoked in the device's <SPAN
2832 >device_name file. For instructions, see <A
2833 HREF="c12776.html#HDRWQ277"
2834 >Invoking a Device's Tape
2835 Mounting and Unmounting Routines</A
2840 >You can configure any tape device or backup data file's <SPAN
2846 >device_name file to
2847 take advantage of the Backup System's automation features. See <A
2848 HREF="c12776.html#HDRWQ275"
2849 >Automating and Increasing the
2850 Efficiency of the Backup Process</A
2855 >When you issue a <SPAN
2861 > command in regular (noninteractive) mode, the command
2862 shell prompt does not return until the operation completes. To avoid having to open additional connections, issue the
2869 > command in interactive mode, especially when including the <SPAN
2875 > argument to schedule dump operations.</P
2879 >An incremental dump proceeds most smoothly if there is a dump created at the dump level immediately above the
2880 level you are using. If the Backup System does not find a Backup Database record for a dump created at the immediate
2881 parent level, it looks for a dump created at one level higher in the hierarchy, continuing up to the full dump level if
2882 necessary. It creates an incremental dump at the level one below the lowest valid parent dump that it finds, or even
2883 creates a full dump if that is necessary. This algorithm guarantees that the dump captures all data that has changed
2884 since the last dump, but has a couple of disadvantages. First, the Backup System's search through the database for a
2885 valid parent dump takes extra time. Second, the subsequent pattern of dumps can be confusing to a human operator who
2886 needs to restore data from them, because they were not performed at the expected dump levels.</P
2888 >The easiest way to guarantee that a dump exists at the immediate parent level is always to perform dump operations
2889 on the predetermined schedule. To check that the parent dump exists, you can issue the <SPAN
2896 > command (as described in <A
2897 HREF="c15383.html#HDRWQ303"
2898 >To display dump records</A
2899 >) and search for it
2900 in the output. Alternatively, issue the <SPAN
2906 > command (as described in <A
2907 HREF="c15383.html#HDRWQ304"
2908 >To display a volume's dump history</A
2909 >) for a volume that you believe is in the parent
2914 >Always use dump levels from the same hierarchy (levels that are descendants of the same full level) when dumping a
2915 given volume set. The result of alternating between levels from different hierarchies can be confusing when you need to
2916 restore data or read dump records. It also increases the chance that changed data is not captured in any dump, or is
2917 backed up redundantly into more than one dump.</P
2921 >Use permanent tape names rather than AFS tape names. You can make permanent names more descriptive than is allowed
2922 by an AFS tape name's strict format, and also bypass the name-checking step that the Backup System performs by default
2923 when a tape has an AFS tape name only. You can also configure the Tape Coordinator always to skip the check, however;
2924 for instructions and a description of the acceptable format for AFS tape names, see <A
2925 HREF="c12776.html#HDRWQ280"
2927 the AFS Tape Name Check</A
2932 >If you write dumps to tape, restore operations are simplest if all of your tape devices are compatible (can read
2933 the same type of tape, at the same compression ratios, and so on). If you must use incompatible devices, then at least
2934 use compatible devices for all dumps performed at dump levels that are at the same depth in their respective hierarchies
2935 (compatible devices for all dumps performed at a full dump level, compatible devices for all dumps performed at a level
2936 1 incremental dump level, and so on). The <SPAN
2942 > argument to the <SPAN
2946 >backup diskrestore</B
2952 >backup volsetrestore</B
2955 multiple port offset numbers, but uses the first listed port offset when restoring all full dumps, the second port
2956 offset when restoring all level 1 dumps, and so on. If you did not use compatible tape devices when creating dumps at
2957 the same depth in a hierarchy, you must restore one volume at a time with the <SPAN
2968 >In some cases, it makes sense to use a <SPAN
2974 > volume set, which exists only within the
2975 context of the interactive session in which it is created and for which no record is created in the Backup Database. One
2976 suitable situation is when dumping a volume to tape in preparation for removing it permanently (perhaps because its
2977 owner is leaving the cell). In this case, you can define a volume entry that includes only the volume of interest
2978 without cluttering up the Backup Database with a volume set record that you are using only once.</P
2982 >Do not perform a dump operation when you know that there are network, machine, or server process problems that can
2983 prevent the Backup System from accessing volumes or the Volume Location Database (VLDB). Although the Backup System
2984 automatically makes a number of repeated attempts to get to an inaccessible volume, the dump operation takes extra time
2985 and in some cases stops completely to prompt you for instructions on how to continue. Furthermore, if the Backup
2986 System's last access attempt fails and the volume is omitted from the dump, you must take extra steps to have it backed
2987 up (namely, the steps described just following for a halted dump operation). For a more complete description of how the
2988 Backup System makes repeated access attempts, see <A
2989 HREF="c15383.html#HDRWQ298"
2990 >How Your Configuration Choices Influence the
2996 >Review the logs created by the Backup System as soon as possible after a dump operation completes, particularly if
2997 it ran unattended. They name any volumes that were not successfully backed up, among other problems. The Backup Server
3002 >/usr/afs/logs/BackupLog</B
3004 > file on the local disk of the database server
3005 machine, and you can use the <SPAN
3011 > command to read it remotely if you wish; for
3012 instructions, see <A
3013 HREF="c6449.html#HDRWQ173"
3014 >Displaying Server Process Log Files</A
3015 >. The Tape Coordinator writes to
3016 two files in the local <SPAN
3022 > directory on the machine where it is running:
3029 >device_name file records errors, and the <SPAN
3035 >device_name file records both trace and error messages.</P
3039 >Avoid halting a dump operation (for instance, by issuing the <SPAN
3046 command in interactive mode), both because it introduces the potential for confusion and because recovering from the
3047 interruption requires extra effort. When a dump operation is interrupted, the volumes that were backed up before the
3048 halt signal is received are complete on the tape or in the backup data file, and are usable in restore operations. The
3049 records in the Backup Database about the volumes' dump history accurately show when and at which dump level they were
3050 backed up; to display the records, use the <SPAN
3056 > command as described in <A
3057 HREF="c15383.html#HDRWQ304"
3058 >To display a volume's dump history</A
3061 >However, there is no indication in the dump's Backup Database record that volumes were omitted; to display the
3062 record, use the <SPAN
3068 > command as described in <A
3069 HREF="c15383.html#HDRWQ303"
3071 display dump records</A
3072 >. You must choose one of the following methods for dealing with the volumes that were not
3073 backed up before the dump operation halted. (Actually, you must make the same decision if the dump operation halts for
3074 reasons outside your control.) <UL
3077 >You can take no action, waiting until the next regularly scheduled dump operation to back them up. At that
3078 time, the Backup System automatically dumps them at the appropriate level to guarantee that the dump captures all
3079 of the data that changed since the volume was last dumped. However, you are gambling that restoring the volume is
3080 not necessary before the next dump operation. If restoration is necessary, you can restore the volume only to its
3081 state at the time it was last included in a dump--you have lost all changes made to the volume since that
3086 >You can discard the entire dump and run the dump operation again. To discard the dump, use the <SPAN
3090 >backup labeltape</B
3092 > command to relabel the tapes or backup data file, which automatically
3093 removes all associated records from the Backup Database. For instructions, see <A
3094 HREF="c12776.html#HDRWQ272"
3096 and Reading Tape Labels</A
3097 >. If a long time has passed since the backup version of the volumes was created,
3098 some of the source volumes have possibly changed. If that seems likely, reissue the <SPAN
3111 > command on them before redoing the dump
3116 >You can create a new volume set that includes the missed volumes and dump it at a full dump level (even if
3117 you specify an incremental dump level, the Backup System uses the full dump level at the top of your specified
3118 level's hierarchy, because it has never before backed up these volumes as part of the new volume set). The next
3119 time you dump the original volume set, the Backup System automatically dumps the missed volumes at the level one
3120 below the level it used the last time it dumped the volumes as part of the original volume set.</P
3134 >How Your Configuration Choices Influence the Dump Process</A
3137 >This section provides an overview of the backup process, describing what happens at each stage both by default and as a
3138 result of your configuration choices, including the configuration instructions you include in the device-specific <SPAN
3144 >device_name file. For the sake of clarity, it tracks the progress of a single <SPAN
3150 > command that creates an initial dump. For a discussion of the slight differences in the
3151 procedure when you append or schedule dumps, see <A
3152 HREF="c15383.html#HDRWQ299"
3153 >Appending Dumps to an Existing Dump Set</A
3156 HREF="c15383.html#HDRWQ300"
3157 >Scheduling Dumps</A
3160 >As a concrete example, the following description traces a dump of the volume set <SPAN
3171 >/weekly/mon/tues/wed</B
3173 > dump level. The <SPAN
3180 has one volume entry that matches the backup version of all user volumes:</P
3182 CLASS="programlisting"
3187 >.* .* user.*\.backup</B
3192 >The dump level belongs to the following dump hierarchy.</P
3194 CLASS="programlisting"
3209 >You issue the <SPAN
3215 > command to start a Tape Coordinator
3216 to handle the dump operation. The Tape Coordinator does not have to be running when you issue the <SPAN
3222 > command, but must be active in time to accept the list of volumes to be included in the
3224 HREF="c15383.html#LIBKOV-VOLMATCHES"
3226 > is completed. To avoid coordination problems, it is best to
3227 start the Tape Coordinator before issuing the <SPAN
3235 >As the Tape Coordinator initializes, it reads the entry in its local <SPAN
3239 >/usr/afs/backup/tapeconfig</B
3241 > file for the port offset you specify on the <SPAN
3247 > command line. The entry specifies the name of the device to use, and the Tape Coordinator
3248 verifies that it can access it. It also reads the device's configuration file, <SPAN
3252 >/usr/afs/backup/CFG_</B
3254 >device_name, if it exists. See Step <A
3255 HREF="c15383.html#LIBKOV-READCFG"
3258 a description of how the instructions in the file influence the dump operation.</P
3262 >You issue the <SPAN
3268 > command, specifying a volume set, dump level, and the
3269 same port offset number you specified on the <SPAN
3275 > command in Step <A
3276 HREF="c15383.html#LIBKOV-BUTC"
3278 >. The Backup System verifies that they have correct Backup Database records and halts the
3279 operation with an error message if they do not.</P
3281 >If you issue the command in interactive mode, the Backup System assigns the operation a job ID number, which you can
3282 use to check the operation's status or halt it by using the <SPAN
3294 > command, respectively. For instructions, see <A
3295 HREF="c15383.html#HDRWQ289"
3297 pending or running jobs in interactive mode</A
3299 HREF="c15383.html#HDRWQ290"
3300 >To cancel operations in interactive
3307 NAME="LIBKOV-VOLMATCHES"
3309 >The Backup System works with the VL Server to generate a list of the volumes in the
3310 VLDB that match the name and location criteria defined in the volume set's volume entries. If a volume matches more than
3311 one volume entry, the Backup System ignores the duplicates so that the dump includes only one copy of data from the
3314 >To reduce the number of times you need to switch tapes during a restore operation, the Backup System sorts the
3315 volumes by server machine and partition, and during the dump operation writes the data from all volumes stored on a
3316 specific partition before moving to the next partition.</P
3318 >As previously mentioned, it is best to back up backup volumes rather than read/write volumes, to avoid blocking
3319 users' access to data during the dump. To achieve this, you must explicitly include the <SPAN
3325 > suffix on the volume names in volume entry definitions. For instructions, and to learn how
3326 to define volume entries that match multiple volumes, see <A
3327 HREF="c12776.html#HDRWQ265"
3328 >Defining and Displaying Volume Sets and
3332 >In the example, suppose that 50 volumes match the <SPAN
3338 > volume set criteria,
3339 including three called <SPAN
3349 >user.terry.backup</B
3355 >user.smith.backup</B
3362 NAME="LIBKOV-CLONEDATE"
3364 >The Backup System next scans the dump hierarchy for the dump level you have
3365 specified on the <SPAN
3371 > command line. If it is a full level, then in the current
3372 operation the Backup System backs up all of the data in all of the volumes in the list obtained in Step <A
3373 HREF="c15383.html#LIBKOV-VOLMATCHES"
3377 >If the dump level is incremental, the Backup System reads each volume's dump history in the Backup Database to learn
3378 which of the parent levels in its pathname was used when the volume was most recently backed up as part of this volume
3379 set. In the usual case, it is the current dump level's immediate parent level.</P
3381 >An incremental dump of a volume includes only the data that changed since the volume was included in the parent
3382 dump. To determine which data are eligible, the Backup System uses the concept of a volume's <SPAN
3389 >. A read/write volume's clone date is when the Backup System locks the volume before copying its contents
3390 into a dump. A backup volume's clone date is the completion time of the operation that created it by cloning its
3391 read/write source volume (the operation initiated by a <SPAN
3403 > command). A read-only volume's clone date is the time of the release operation
3404 (initiated by the <SPAN
3410 > command) that completed most recently before the dump
3413 >More precisely then, an incremental dump includes only data that have a modification timestamp between the clone
3414 date of the volume included in the parent dump (the <SPAN
3418 >parent clone date</I
3420 >) and the clone date of the
3421 volume to be included in the current dump (the <SPAN
3425 >current clone date</I
3429 >There are some common exceptions to the general rule that a volume's parent dump is the dump created at the
3430 immediate parent level: <UL
3433 >The volume did not exist at all at the time of the last dump. In this case, the Backup System automatically
3434 does a full dump of it.</P
3438 >The volume did not match the volume set's name and location criteria at the time of the last dump. In this
3439 case, the Backup System automatically does a full dump of it, even if it was backed up recently (fully or
3440 incrementally) as part of another volume set. This redundancy is an argument for defining volume entries in terms of
3441 names rather than locations, particularly if you move volumes frequently.</P
3445 >The volume was not included in the dump at the immediate parent level for some reason (perhaps a process,
3446 machine, or network access prevented the Backup System from accessing it). In this case, the Backup System sets the
3447 clone date to the time of the last dump operation that included the volume. If the volume was not included in a dump
3448 performed at any of the levels in the current level's pathname, the Backup System does a full dump of it.</P
3453 >In the example, the current dump level is <SPAN
3457 >/weekly/mon/tues/wed</B
3469 >user.terry.backup</B
3471 > volumes were included in the
3472 dump performed yesterday, Tuesday, at the <SPAN
3476 >/weekly/mon/tues</B
3478 > level. The Backup System uses
3479 as their parent clone date 3:00 a.m. on Tuesday, which is when backup versions of them were created just before Tuesday's
3480 dump operation. However, Tuesday's dump did not include the <SPAN
3484 >user.smith.backup</B
3487 some reason. The last time it was included in a dump was Monday, at the <SPAN
3494 level. The Backup System uses a parent clone date of Monday at 2:47 a.m., which is when a backup version of the volume was
3495 created just before the dump operation on Monday.</P
3499 >If performing an incremental dump, the Backup System works with the Volume Server to prepare a list of all of the
3500 files in each volume that have changed (have modification timestamps) between the parent clone date and the current clone
3501 date. The dump includes the complete contents of every such file. If a file has not changed, the dump includes only a
3502 placeholder stub for it. The dump also includes a copy of the complete directory structure in the volume, whether or not
3503 it has changed since the previous dump.</P
3505 >If none of the data in the volume has changed since the last dump, the Backup System omits the volume completely. It
3506 generates the following message in the Tape Coordinator window and log files:</P
3508 CLASS="programlisting"
3509 > Volume volume_name (volume_ID) not dumped - has not been modified
3516 NAME="LIBKOV-READCFG"
3518 >The Tape Coordinator prepares to back up the data. If there is a <SPAN
3524 >device_name file, the Tape Coordinator already read it in Step <A
3525 HREF="c15383.html#LIBKOV-BUTC"
3527 >. The following list describes how the instructions in the file guide the Tape Coordinator's
3528 behavior at this point: <DIV
3529 CLASS="variablelist"
3541 >If this instruction is set to <SPAN
3547 >, the Tape Coordinator writes data to a
3548 backup data file. The device_name field in the <SPAN
3554 > file must also specify
3555 a filename for the dump to work properly. For further discussion and instructions on configuring a backup data
3557 HREF="c12776.html#HDRWQ282"
3558 >Dumping Data to a Backup Data File</A
3561 >If it is set to <SPAN
3567 > or does not appear in the file, the Tape Coordinator
3568 writes to a tape device.</P
3575 >MOUNT and UNMOUNT</B
3580 >If there is a <SPAN
3586 > instruction in the file, each time the Tape Coordinator
3587 needs a new tape, it invokes the indicated script or program to mount a tape in the device's tape drive. There
3594 > instruction if you want to utilize a tape stacker or jukebox's
3595 ability to switch between tapes automatically. If there is no <SPAN
3602 the Tape Coordinator prompts the human operator whenever it needs a tape.</P
3610 > instruction, which is described just following, modifies the
3611 Tape Coordinator's tape acquisition procedure for the first tape it needs in a dump operation.</P
3613 >If there is an <SPAN
3619 > instruction, then the Tape Coordinator invokes the
3620 indicated script or program whenever it closes the tape device. Not all tape devices have a separate tape
3621 unmounting routine, in which case the <SPAN
3627 > instruction is not necessary. For
3628 more details on both instructions, see <A
3629 HREF="c12776.html#HDRWQ277"
3630 >Invoking a Device's Tape Mounting and Unmounting
3644 >If this instruction is set to <SPAN
3650 >, the Tape Coordinator assumes that the
3651 first tape needed for the dump operation is already in the tape drive. It does not use its usual tape acquisition
3652 procedure as described in the preceding discussion of the <SPAN
3659 can achieve the same effect by including the <SPAN
3673 >If this instruction is absent or set to <SPAN
3679 >, the Tape Coordinator uses its
3680 usual tape acquisition procedure even for the first tape. For more details, see <A
3681 HREF="c12776.html#HDRWQ278"
3682 >Eliminating the Search or Prompt for the Initial Tape</A
3695 >If this instruction appears in the file, the Tape Coordinator sets its buffer size to the specified value
3696 rather than using the default buffer size of 16 KB. For further discussion, see <A
3697 HREF="c12776.html#HDRWQ281"
3699 the Memory Buffer Size to Promote Tape Streaming</A
3706 >If there is no <SPAN
3712 >device_name file, the Tape Coordinator writes data to a tape
3713 device and prompts the human operator each time it needs a tape (the only exception being the first tape if you include
3731 NAME="LIBKOV-NAMECHECK"
3733 >The Tape Coordinator opens either a tape drive or backup data file at this point, as
3734 directed by the instructions in the <SPAN
3740 >device_name file (described in Step <A
3741 HREF="c15383.html#LIBKOV-READCFG"
3743 >). The instructions also determine whether it invokes a mount script or prompts the
3744 operator. In Step <A
3745 HREF="c15383.html#LIBKOV-BUTC"
3747 > the Tape Coordinator read in the device's capacity and filemark
3754 > file. It now reads the same values from the tape or backup data
3755 file's magnetic label, and overwrites the <SPAN
3761 > values if there is a
3764 >If creating an initial dump (as in the current example) and there is no permanent name on the label, the Tape
3765 Coordinator next checks that the AFS tape name has one of the three acceptable formats. If not, it rejects the tape and
3766 you must use the <SPAN
3770 >backup labeltape</B
3772 > command to write an acceptable name. You can bypass
3773 this name-checking step by including the <SPAN
3779 > instruction in the <SPAN
3785 >device_name file. For discussion and a list of the acceptable AFS tape name values, see <A
3786 HREF="c12776.html#HDRWQ280"
3787 >Eliminating the AFS Tape Name Check</A
3793 NAME="LIBKOV-EXPDATE"
3795 >For an initial dump, the Tape Coordinator starts writing at the beginning of the tape
3796 or backup dump file, overwriting any existing data. To prevent inappropriate overwriting, the Backup System first checks
3797 the Backup Database for any dump records associated with the name (permanent or AFS tape name) on the tape or backup dump
3798 file's label. It refuses to write to a backup data file that has unexpired dumps in it, or to a tape that belongs to a
3799 dump set with any unexpired dumps. To recycle a file or tape before all dumps have expired, you must use the <SPAN
3803 >backup labeltape</B
3805 > command to relabel it. Doing so removes the Backup Database records of all dumps
3806 in the file or on all tapes in the dump set, which makes it impossible to restore data from any of the tapes. For more
3807 information on expiration dates, see <A
3808 HREF="c12776.html#HDRWQ270"
3809 >Defining Expiration Dates</A
3812 >The Tape Coordinator also checks for two other types of inappropriate tape reuse. The tape cannot already have data
3813 on it that belongs to the dump currently being performed, because that implies that the previous tape is still in the
3814 drive, or you have mistakenly reinserted it. The Tape Coordinator generates the following message and attempts to obtain
3817 CLASS="programlisting"
3818 > Can't overwrite tape containing the dump in progress
3821 >The tape cannot contain data from a parent dump of the current (incremental) dump, because overwriting a parent dump
3822 makes it impossible to restore data from the current dump. The Tape Coordinator generates the following message and
3823 attempts to obtain another tape:</P
3825 CLASS="programlisting"
3826 > Can't overwrite the parent dump parent_name (parent_dump_ID)
3834 >The Tape Coordinator now writes data to the tape or backup data file. It uses the
3835 capacity and filemark size it obtained in Step <A
3836 HREF="c15383.html#LIBKOV-NAMECHECK"
3838 > as it tracks how much more space
3839 is available, automatically using its tape acquisition procedure if the dump is not finished when it reaches the end of
3840 the tape. For a more detailed description, and a discussion of what happens if the Tape Coordinator reaches the physical
3841 end-of-tape unexpectedly, see <A
3842 HREF="c12776.html#HDRWQ258"
3843 >Configuring the tapeconfig File</A
3844 >. Similarly, for instructions
3845 on configuring a backup data file to optimize recovery from unexpectedly running out of space, see Step <A
3846 HREF="c12776.html#LITAPECONFIG-FILE"
3848 > in the instructions in <A
3849 HREF="c12776.html#HDRWQ282"
3850 >Dumping Data to a Backup Data
3854 >If the Tape Coordinator cannot access a volume during the dump (perhaps because of a server process, machine, or
3855 network outage), it skips the volume and continues dumping all volumes that it can access. It generates an error message
3856 in the Tape Coordinator window and log file about the omitted volume. It generates a similar message if it discovers that
3857 a backup volume has not been recloned since the previous dump operation (that is, that the volume's current clone date is
3858 the same as its parent clone date):</P
3860 CLASS="programlisting"
3861 > Volume volume_name (volume_ID) not dumped - has not been re-cloned
3865 >After completing a first pass through all of the volumes, it attempts to dump each omitted volume again. It first
3866 checks to see if the reason that the volume was inaccessible during the first pass is that it has been moved since the VL
3867 Server generated the list of volumes to dump in Step <A
3868 HREF="c15383.html#LIBKOV-VOLMATCHES"
3870 >. If so, it dumps the
3871 volume from its new site. If the second attempt to access a volume also fails, the Tape Coordinator it generates the
3872 following message, prompting you for instruction on how to proceed:</P
3874 CLASS="programlisting"
3875 > Dump of volume volume_name (volume_ID) failed
3876 Please select action to be taken for this volume.
3877 r - retry, try dumping this volume again
3878 o - omit, this volume from this dump
3879 a - abort, the entire dump
3882 >To increase the automation of the dump process, you can include the <SPAN
3889 instruction in the <SPAN
3895 >device_name file to suppress this prompt and have the Tape
3896 Coordinator automatically omit the volume from the dump.</P
3898 >If you are tracking the dump as it happens, the prompt enables you to take corrective action. If the volume has not
3899 been recloned, you can issue the <SPAN
3905 > command. If the volume is inaccessible, you
3906 can investigate and attempt to resolve the cause.</P
3910 >If the tape or backup data file does not already have an AFS tape name, the Backup System constructs the appropriate
3911 one and records it on the label and in the Backup Database. It also assigns a dump name and ID number to the dump and
3912 records them in dump record that it creates in the Backup Database. For details on tape and dump names, see <A
3913 HREF="c12776.html#HDRWQ253"
3914 >Dump Names and Tape Names</A
3915 >. For instructions on displaying dump records or a volume's dump
3916 history, or scanning the contents of a tape, see <A
3917 HREF="c15383.html#HDRWQ302"
3918 >Displaying Backup Dump Records</A
3929 >Appending Dumps to an Existing Dump Set</A
3932 >The AFS Backup System enables you to append dumps to the end of the final tape in a dump set by including the <SPAN
3944 > command. Appending dumps improves
3945 Backup System automation and efficiency in several ways: <UL
3948 >It maximizes use of a tape's capacity. An initial dump must always start on a new tape, but does not necessarily
3949 extend to the end of the final tape in the dump set. You can fill up the unused tape by appending one or more
3954 >It can reduce the number of tapes and tape changes needed to complete a dump operation. Rather than performing a
3955 series of initial dumps first, instead begin with an initial dump and follow it immediately with several appended dumps.
3956 In this way you can write all dumps in the series to the same tape (assuming the tape is large enough to accommodate
3957 them all). If, in contrast, you perform all of the initial dumps first, each must begin on a new tape and you must
3958 switch tapes again if you then want to append dumps.</P
3960 >You can either issue the appropriate series of <SPAN
3968 CLASS="computeroutput"
3970 > prompt, or record them in a file that you then name with the
3977 > argument to the <SPAN
3983 > command. Appending
3984 dumps in this way enables you to run multiple unattended backup operations even without a tape stacker or jukebox, if
3985 all of the dumps fit on one tape.</P
3989 >It can reduce the number of tape changes during a restore operation. For example, if you append all of the
3990 incremental dumps of a volume set to tapes in one dump set, then restoring a volume from the volume set requires a
3991 minimum number of tape changes. It is best not to append incremental dumps to a tape that contains the parent full dump,
3992 however: if the tape is lost or damaged, you lose all of the data from the volume.</P
3994 >Although it can be efficient to group together appended dumps that are related, the Backup System does not require
3995 any relationship between the appended dumps on a tape or in a dump set.</P
4000 >When writing an appended dump, the Backup System performs most of the steps described in <A
4001 HREF="c15383.html#HDRWQ298"
4003 Your Configuration Choices Influence the Dump Process</A
4004 >. Appended dumps do not have to be related to one another or the
4005 initial dump, so it skips Step <A
4006 HREF="c15383.html#LIBKOV-NAMECHECK"
4008 >: there is no need to check that the AFS tape name
4009 reflects the volume set and dump level names in this case. It also skips Step <A
4010 HREF="c15383.html#LIBKOV-EXPDATE"
4013 it is not overwriting any existing data on the tape, it does not need to check the expiration dates of existing dumps on the
4014 tape or in the file. Then in Step <A
4015 HREF="c15383.html#LIBKOV-WRITE"
4017 > the Tape Coordinator scans to the end of the last dump
4018 on the tape or in the backup data file before it begins writing data.</P
4020 >The Backup System imposes the following conditions on appended dumps: <UL
4023 >If writing to tape, the Tape Coordinator checks that it is the final one in a dump set for which there are
4024 complete and valid tape and dump records in the Backup Database. If not, it rejects the tape and requests an acceptable
4025 one. If you believe the tape has valid data on it, you can reconstruct the Backup Database dump records for it by using
4032 > argument to the <SPAN
4040 HREF="c15383.html#HDRWQ305"
4041 >To scan the contents of a tape</A
4046 >The most recent dump on the tape or in the backup data file must have completed successfully.</P
4050 >The dump set to which the tape or file belongs must begin with an initial dump that is recorded in the Backup
4051 Database. If there are no dumps on the current tape, then the Backup System treats the dump operation as an initial dump
4052 and imposes the relevant requirements (for example, checks the AFS tape name if appropriate).</P
4057 >As you append dumps, keep in mind that all of a dump set's dump and tape records in the Backup Database are indexed to
4058 the initial dump. If you want to delete an appended dump's record, you must delete the initial dump record, and doing so
4059 erases the records of all dumps in the dump set. Without those records, you cannot restore any of the data in the dump
4062 >Similarly, all of the dumps in a dump set must expire before you can recycle (write a new initial dump to) any of the
4063 tapes in a dump set. Do not append a dump if its expiration date is later than the date on which you want to recycle any of
4064 the tapes in its dump set. To recycle a tape before the last expiration date, you must delete the initial dump's record from
4065 the Backup Database. Either use the <SPAN
4069 >backup labeltape</B
4071 > command to relabel the tape as
4073 HREF="c12776.html#HDRWQ273"
4079 >backup deletedump</B
4082 command to delete the record directly as instructed in <A
4083 HREF="c15383.html#HDRWQ322"
4084 >To delete dump records from the Backup
4088 >Although in theory you can append as many dumps as you wish, it generally makes sense to limit the number of tapes in a
4089 dump set (for example, to five), for these reasons: <UL
4092 >If an unreadable spot develops on one of the tapes in a dump set, it can prevent the Tape Coordinator from
4093 scanning the tape as part of a <SPAN
4099 > operation you use to reconstruct Backup
4100 Database records. The Tape Coordinator can almost always scan the tape successfully up to the point of damage and can
4101 usually skip past minor damage. A scanning operation can start on any tape in a dump set, so damage on one tape does not
4102 prevent scanning of the others in the dump set. However, you can scan only the tapes that precede the damaged one in the
4103 dump set or the ones that follow the damaged one, but not both. (For more information on using tapes to reconstruct the
4104 information in the Backup Database, see <A
4105 HREF="c15383.html#HDRWQ305"
4106 >To scan the contents of a tape</A
4109 >An unreadable bad spot can also prevent you from restoring a volume completely, because restore operations must
4110 begin with the full dump and continue with each incremental dump in order. If you cannot restore a specific dump, you
4111 cannot restore any data from later incremental dumps.</P
4115 >If you decide in the future to archive one or more dumps, then you must archive the entire set of tapes that
4116 constitute the dump set, rather than just the ones that contain the data of interest. This wastes both tape and archive
4117 storage space. For more information on archiving, see <A
4118 HREF="c12776.html#HDRWQ269"
4131 >Scheduling Dumps</A
4134 >By default, the Backup System starts executing a dump operation as soon as you enter the <SPAN
4141 > command, and the Tape Coordinator begins writing data as soon as it is not busy and the list of files to write
4142 is available. You can, however, schedule a dump operation to begin at a specific later time: <UL
4145 >To schedule a single dump operation, include the <SPAN
4151 > argument to specify its
4156 >To schedule multiple dump operations, list the operations in a file named by the <SPAN
4162 > argument and use the <SPAN
4168 > argument to specify when the
4175 > command interpreter reads the file. If you omit the <SPAN
4181 > argument, the command interpreter reads the file immediately, which does not count as
4182 scheduling, but does allow you to initiate multiple dump operations in a single command. Do not combine the <SPAN
4188 > argument with the <SPAN
4221 >For file-formatting instructions, see the description of the <SPAN
4229 HREF="c15383.html#LIBKDUMP-SYNTAX"
4232 HREF="c15383.html#HDRWQ301"
4233 >To create a dump</A
4239 >The Backup System performs initial and appended dumps in the same manner whether they are scheduled or begin running as
4240 soon as you issue the <SPAN
4246 > command. The only difference is that the requirements for
4247 successful execution hold both at the time you issue the command and when the Backup System actually begins running it. All
4248 required Backup Database entries for volume sets, dump levels, and port offsets, and all dump and tape records must exist at
4249 both times. Perhaps more importantly, the required administrative tokens must be available at both times. See <A
4250 HREF="c15383.html#HDRWQ297"
4251 >Making Backup Operations More Efficient</A
4260 >To create a dump</A
4266 >Verify that you are authenticated as a user listed in the <SPAN
4270 >/usr/afs/etc/UserList</B
4273 file. If necessary, issue the <SPAN
4279 > command, which is fully described in <A
4280 HREF="c32432.html#HDRWQ593"
4281 >To display the users in the UserList file</A
4283 CLASS="programlisting"
4302 >If the Tape Coordinator for the tape device that is to perform the operation is not already running, open a
4303 connection to the appropriate Tape Coordinator machine and issue the <SPAN
4310 which complete instructions appear in <A
4311 HREF="c15383.html#HDRWQ292"
4312 >To start a Tape Coordinator process</A
4315 CLASS="programlisting"
4340 >If using a tape device, insert the tape.</P
4350 > command to enter interactive mode. <PRE
4351 CLASS="programlisting"
4364 >Decide which volume set and dump level to use. If necessary, issue the <SPAN
4375 >backup listdumps</B
4377 > commands to display the existing volume sets
4378 and dump levels. For complete instructions and a description of the output, see <A
4379 HREF="c12776.html#HDRWQ266"
4381 sets and volume entries</A
4383 HREF="c12776.html#HDRWQ271"
4384 >To display the dump hierarchy</A
4386 CLASS="programlisting"
4387 > backup> <SPAN
4410 >If you want to use a temporary volume set, you must create it during the current interactive session. This can be
4411 useful if you are dumping a volume to tape in preparation for removing it permanently (perhaps because its owner is
4412 leaving the cell). In this case, you can define a volume entry that includes only the volume of interest without
4413 cluttering up the Backup Database with a volume set record that you are using only once. Complete instructions appear in
4415 HREF="c12776.html#HDRWQ265"
4416 >Defining and Displaying Volume Sets and Volume Entries</A
4419 CLASS="programlisting"
4420 > backup> <SPAN
4443 >addvolentry -name</B
4488 >volume name (regular expression)</I
4495 >If you are creating an initial dump and writing to a tape or backup data file that does not have a permanent name,
4496 its AFS tape name must satisfy the Backup System's format requirements as described in <A
4497 HREF="c12776.html#HDRWQ280"
4498 >Eliminating the AFS Tape Name Check</A
4499 >. If necessary, use the <SPAN
4506 > command to display the label and the <SPAN
4510 >backup labeltape</B
4513 change the names, as instructed in <A
4514 HREF="c12776.html#HDRWQ272"
4515 >Writing and Reading Tape Labels</A
4516 >. You must also relabel
4517 a tape if you want to overwrite it and it is part of a dump set that includes any unexpired dumps, though this is not
4518 recommended. For a discussion of the appropriate way to recycle tapes, see <A
4519 HREF="c12776.html#HDRWQ268"
4521 Recycling Schedule</A
4527 NAME="LIBKDUMP-SYNTAX"
4535 > command to dump the volume
4539 >To create one initial dump, provide only the volume set name, dump level name, and port offset (if not
4544 >To create one appended dump, add the <SPAN
4554 >To schedule a single initial or appended dump, add the <SPAN
4564 >To initiate multiple dump operations, record the appropriate commands in a file and name it with the <SPAN
4570 > argument. Do not combine this argument with options other than the <SPAN
4581 CLASS="programlisting"
4582 > backup> <SPAN
4617 >Date/time to start dump</I
4648 CLASS="variablelist"
4660 >Must be typed in full.</P
4672 >Names the volume set to dump.</P
4684 >Specifies the complete pathname of the dump level at which to dump the volume set.</P
4696 >Specifies the port offset number of the Tape Coordinator process that is handling the operation. You must
4697 provide this argument unless the default value of 0 (zero) is appropriate.</P
4709 >Specifies the date and time in the future at which to run the command, or to read the file named by the
4716 > argument. Provide a value in the format mm/dd/yyyy [hh:MM], where the month
4717 (mm), day (dd), and year (yyyy) are required. Valid values for the year range from <SPAN
4729 >; higher values are not valid because the
4730 latest possible date in the standard UNIX representation is in February 2038. The Backup System automatically
4731 reduces any later date to the maximum value in 2038.</P
4733 >The hour and minutes (hh:MM) are optional, but if provided must be in 24-hour format (for example, the value
4740 > represents 2:36 p.m.). If you omit them, the time defaults to midnight
4743 >As an example, the value <SPAN
4747 >04/23/1999 20:20</B
4749 > schedules the command for 8:20
4750 p.m. on 23 April 1999.</P
4758 >A plus sign follows this argument in the command's syntax statement because it accepts a multiword value
4759 which does not need to be enclosed in double quotes or other delimiters, not because it accepts multiple dates.
4760 Provide only one date (and optionally, time) definition.</P
4774 >Creates an appended dump by scanning to the end of the data from one or more previous dump operations that
4775 it finds on the tape or in the backup data file.</P
4787 >Displays the names of all volumes to be included in the indicated dump, without actually writing data to
4788 tape or the backup data file. Combine this flag with the arguments you plan to use on the actual command, but not
4807 >Specifies the local disk or AFS pathname of a file containing <SPAN
4814 commands. The Backup System reads the file immediately, or at the time specified by the <SPAN
4820 > argument if it is provided. A partial pathname is interpreted relative to the current
4821 working directory.</P
4829 > command on its own line in the indicated file, using
4830 the same syntax as for the command line, but without the word <SPAN
4837 of the line. Each command must include the volume set name and dump level name arguments plus the TC port offset
4838 argument if the default value of zero is not appropriate. Commands in the file can also include any of the
4845 > command's optional arguments, including the <SPAN
4851 > argument (which must specify a date and time later than the date and time at which the
4852 Backup System reads the file).</P
4860 >If you did not include the <SPAN
4866 > flag when you issued the <SPAN
4872 > command, or if the device's <SPAN
4878 >device_name configuration
4879 file includes the instruction <SPAN
4885 >, then the Tape Coordinator prompts you to
4886 place the tape in the device's drive. You have already done so, but you must now press <<SPAN
4892 >> to indicate that the tape is ready for labeling.</P
4894 >If more than one tape is required, you must either include the <SPAN
4907 >device_name file and stock the corresponding stacker or jukebox with tapes, or
4908 remain at the console to respond to the Tape Coordinator's prompts for subsequent tapes.</P
4912 >After the dump operation completes, review the Backup System's log files to check for errors. Use the <SPAN
4918 > command as instructed in <A
4919 HREF="c6449.html#HDRWQ173"
4920 >Displaying Server Process Log
4926 >/usr/afs/logs/BackupLog</B
4928 > file, and a text editor on the Tape
4929 Coordinator machine to read the <SPAN
4935 >device_name and <SPAN
4941 >device_name files in the local <SPAN
4950 >It is also a good idea to record the tape name and dump ID number on the exterior label of each tape.</P
4961 >Displaying Backup Dump Records</A
4970 > command suite includes three commands for displaying information about data
4971 you have backed up: <UL
4974 >To display information about one or more dump operations, such as the date it was performed and the number of
4975 volumes included, use the <SPAN
4981 > command as described in <A
4982 HREF="c15383.html#HDRWQ303"
4983 >To display dump records</A
4984 >. You can display a detailed record of a single dump or more condensed
4985 records for a certain number of dumps, starting with the most recent and going back in time. You can specify the number of
4986 dumps or accept the default of 10.</P
4990 >To display a volume's dump history, use the <SPAN
4996 > command as described in
4998 HREF="c15383.html#HDRWQ304"
4999 >To display a volume's dump history</A
5004 >To display information extracted from a tape or backup data file about the volumes it includes, use the <SPAN
5010 > command. To create new dump and tape records in the Backup Database derived from
5011 the tape and dump labels, add the <SPAN
5017 > flag. For instructions, see <A
5018 HREF="c15383.html#HDRWQ305"
5019 >To scan the contents of a tape</A
5030 >To display dump records</A
5036 >Verify that you are authenticated as a user listed in the <SPAN
5040 >/usr/afs/etc/UserList</B
5043 file. If necessary, issue the <SPAN
5049 > command, which is fully described in <A
5050 HREF="c32432.html#HDRWQ593"
5051 >To display the users in the UserList file</A
5053 CLASS="programlisting"
5078 > command to list information about dumps recorded in the
5079 Backup Database. <PRE
5080 CLASS="programlisting"
5122 CLASS="variablelist"
5134 >Is the shortest acceptable abbreviation of <SPAN
5152 >Displays the Backup Database record for each of the specified number of dumps, starting with the most recent
5153 and going back in time. If the database contains fewer dumps than are requested, the output includes the records
5154 for all existing dumps. Do not combine this argument with the <SPAN
5167 > flag; omit all three options to display the records for the last 10
5180 >Specifies the dump ID number of a single dump for which to display the Backup Database record. You must
5187 > switch. Do not combine this option with the <SPAN
5199 > arguments; omit all three arguments to
5200 display the records for the last 10 dumps.</P
5212 >Provides more detailed information about the dump specified with the <SPAN
5219 argument, which must be provided along with it. Do not combine this flag with the <SPAN
5239 > argument is provided, the output presents the following information in
5240 table form, with a separate line for each dump: <DIV
5241 CLASS="variablelist"
5249 CLASS="computeroutput"
5256 >The dump ID number.</P
5264 CLASS="computeroutput"
5271 >The dump ID number of the dump's parent dump. A value of <SAMP
5272 CLASS="computeroutput"
5274 > (zero) identifies a
5283 CLASS="computeroutput"
5290 >The depth in the dump hierarchy of the dump level used to create the dump. A value of
5292 CLASS="computeroutput"
5294 > (zero) identifies a full dump, in which case the value in the
5296 CLASS="computeroutput"
5298 > field is also <SAMP
5299 CLASS="computeroutput"
5303 CLASS="computeroutput"
5305 > or greater indicates an incremental dump made at the corresponding level in the
5314 CLASS="computeroutput"
5321 >The date and time at which the Backup System started the dump operation that created the dump.</P
5329 CLASS="computeroutput"
5336 >The number of tapes that contain the data in the dump. A value of <SAMP
5337 CLASS="computeroutput"
5340 indicates that the dump operation was terminated or failed. Use the <SPAN
5344 >backup deletedump</B
5347 command to remove such entries.</P
5355 CLASS="computeroutput"
5362 >The number of volumes from which the dump includes data. If a volume spans tapes, it is counted twice. A value
5364 CLASS="computeroutput"
5366 > (zero) indicates that the dump operation was terminated or failed; the value in
5368 CLASS="computeroutput"
5370 > field is also <SAMP
5371 CLASS="computeroutput"
5373 > (zero) in this case.</P
5381 CLASS="computeroutput"
5388 >The dump name in the form <PRE
5389 CLASS="programlisting"
5390 > volume_set_name.dump_level_name (initial_dump_ID)
5394 >where volume_set_name is the name of the volume set, and dump_level_name is the last element in the dump level
5395 pathname at which the volume set was dumped.</P
5397 >The initial_dump_ID, if displayed, is the dump ID of the initial dump in the dump set to which this dump
5398 belongs. If there is no value in parentheses, the dump is the initial dump in a dump set that has no appended
5411 > argument is provided alone, the first line of output begins with the string
5413 CLASS="computeroutput"
5415 > and reports information for the entire dump in the following fields: <DIV
5416 CLASS="variablelist"
5424 CLASS="computeroutput"
5431 >The dump ID number.</P
5439 CLASS="computeroutput"
5446 >The depth in the dump hierarchy of the dump level used to create the dump. A value of
5448 CLASS="computeroutput"
5450 > (zero) identifies a full dump. A value of <SAMP
5451 CLASS="computeroutput"
5454 or greater indicates an incremental dump made at the specified level in the dump hierarchy.</P
5462 CLASS="computeroutput"
5469 >The number of volumes for which the dump includes data.</P
5477 CLASS="computeroutput"
5484 >The date and time at which the dump operation began.</P
5490 >If an XBSA server was the backup medium for the dump (rather than a tape device or backup data file), the following line
5493 CLASS="programlisting"
5494 > Backup Service: XBSA_program: Server: hostname
5497 >where XBSA_program is the name of the XBSA-compliant program and hostname is the name of the machine on which the
5500 >Next the output includes an entry for each tape that houses volume data from the dump. Following the string
5502 CLASS="computeroutput"
5504 >, the first two lines of each entry report information about that tape in the following
5506 CLASS="variablelist"
5514 CLASS="computeroutput"
5521 >The tape's permanent name if it has one, or its AFS tape name otherwise, and its tape ID number in
5530 CLASS="computeroutput"
5537 >The number of volumes for which this tape includes dump data.</P
5545 CLASS="computeroutput"
5552 >The date and time at which the Tape Coordinator began writing data to this tape.</P
5558 >Following another blank line, the tape-specific information concludes with a table that includes a line for each volume
5559 dump on the tape. The information appears in columns with the following headings: <DIV
5560 CLASS="variablelist"
5568 CLASS="computeroutput"
5575 >The relative position of each volume in this tape or file. On a tape, the counter begins at position 2 (the tape
5576 label occupies position 1), and increments by one for each volume. For volumes in a backup data file, the position
5577 numbers start with 1 and do not usually increment only by one, because each is the ordinal of the 16 KB offset in the
5578 file at which the volume's data begins. The difference between the position numbers therefore indicates how many 16 KB
5579 blocks each volume's data occupies. For example, if the second volume is at position 5 and the third volume in the
5580 list is at position 9, that means that the dump of the second volume occupies 64 KB (four 16-KB blocks) of space in
5589 CLASS="computeroutput"
5596 >For a backup or read-only volume, the time at which it was cloned from its read/write source. For a Read/Write
5597 volume, it is the same as the dump creation date reported on the first line of the output.</P
5605 CLASS="computeroutput"
5612 >The number of bytes of data in the dump of the volume.</P
5620 CLASS="computeroutput"
5627 >The volume name, complete with <SAMP
5628 CLASS="computeroutput"
5632 CLASS="computeroutput"
5634 > extension if appropriate.</P
5652 > options are provided, the
5653 output is divided into several sections: <UL
5656 >The first section, headed by the underlined string <SAMP
5657 CLASS="computeroutput"
5659 >, includes information
5660 about the entire dump. The fields labeled <SAMP
5661 CLASS="computeroutput"
5664 CLASS="computeroutput"
5668 CLASS="computeroutput"
5671 CLASS="computeroutput"
5673 > report the same values (though
5674 in a different order) as appear on the first line of output when the <SPAN
5681 provided by itself. Other fields of potential interest to the backup operator are: <DIV
5682 CLASS="variablelist"
5690 CLASS="computeroutput"
5703 >, which is recorded in the dump's Backup Database record if
5710 > instruction appears in the Tape Coordinator's <SPAN
5714 >/usr/afs/backup/CFG_</B
5716 >tcid file when the dump is created.</P
5724 CLASS="computeroutput"
5731 >The number of tapes that contain the dump set to which this dump belongs.</P
5739 CLASS="computeroutput"
5740 >Start Tape Seq</SAMP
5746 >The ordinal of the tape on which this dump begins in the set of tapes that contain the dump set.</P
5754 >For each tape that contains data from this dump, there follows a section headed by the underlined string
5756 CLASS="computeroutput"
5758 >. The fields labeled <SAMP
5759 CLASS="computeroutput"
5763 CLASS="computeroutput"
5766 CLASS="computeroutput"
5768 > report the same values (though
5769 in a different order) as appear on the second and third lines of output when the <SPAN
5776 argument is provided by itself. Other fields of potential interest to the backup operator are: <DIV
5777 CLASS="variablelist"
5781 CLASS="computeroutput"
5786 >The date and time when this tape can be recycled, because all dumps it contains have expired.</P
5790 CLASS="computeroutput"
5793 CLASS="computeroutput"
5798 >Summed together, these fields represent the total amount of dumped data actually from volumes (as opposed
5799 to labels, filemarks, and other markers).</P
5803 CLASS="computeroutput"
5804 >KBytes Tape Used</SAMP
5808 >The number of kilobytes of tape (or disk space, for a backup data file) used to store the dump data. It is
5809 generally larger than the sum of the values in the <SAMP
5810 CLASS="computeroutput"
5814 CLASS="computeroutput"
5816 > fields, because it includes the space required for the label, file
5817 marks and other markers, and because the Backup System writes data at 16 KB offsets, even if the data in a given
5818 block doesn't fill the entire 16 KB.</P
5826 >For each volume on a given tape, there follows a section headed by the underlined string
5828 CLASS="computeroutput"
5830 >. The fields labeled <SAMP
5831 CLASS="computeroutput"
5835 CLASS="computeroutput"
5838 CLASS="computeroutput"
5842 CLASS="computeroutput"
5844 > report the same values (though in a different order) as appear in the table that
5845 lists the volumes in each tape when the <SPAN
5851 > argument is provided by itself. Other
5852 fields of potential interest to the backup operator are: <DIV
5853 CLASS="variablelist"
5857 CLASS="computeroutput"
5866 CLASS="computeroutput"
5871 >The name of the tape containing this volume data.</P
5880 >The following example command displays the Backup Database records for the five most recent dump operations.</P
5882 CLASS="programlisting"
5890 dumpid parentid lv created nt nvols dump name
5891 924424000 0 0 04/18/1999 04:26 1 22 usr.sun (924424000)
5892 924685000 924424000 1 04/21/1999 04:56 1 62 usr.wed (924424000)
5893 924773000 924424000 1 04/22/1999 05:23 1 46 usr.thu (924424000)
5894 924860000 924424000 1 04/23/1999 05:33 1 58 usr.fri (924424000)
5895 925033000 0 0 04/25/1999 05:36 2 73 sys.week
5904 >To display a volume's dump history</A
5910 >Verify that you are authenticated as a user listed in the <SPAN
5914 >/usr/afs/etc/UserList</B
5917 file. If necessary, issue the <SPAN
5923 > command, which is fully described in <A
5924 HREF="c32432.html#HDRWQ593"
5925 >To display the users in the UserList file</A
5927 CLASS="programlisting"
5952 > command to display a volume's dump history.
5954 CLASS="programlisting"
5972 CLASS="variablelist"
5984 >Is the shortest acceptable abbreviation of <SPAN
6002 >Names the volume for which to display the dump history. If you dumped the backup or read-only version of the
6003 volume, include the <SPAN
6024 >The output includes a line for each Backup Database dump record that mentions the specified volume, order from most to
6025 least recent. The output for each record appears in a table with six columns: <DIV
6026 CLASS="variablelist"
6030 CLASS="computeroutput"
6035 >The dump ID of the dump that includes the volume.</P
6039 CLASS="computeroutput"
6044 >The depth in the dump hierarchy of the dump level at which the volume was dumped. A value of
6046 CLASS="computeroutput"
6048 > indicates a full dump. A value of <SAMP
6049 CLASS="computeroutput"
6052 indicates an incremental dump made at the specified depth in the dump hierarchy.</P
6056 CLASS="computeroutput"
6061 >The dump ID of the dump's parent dump. A value of <SAMP
6062 CLASS="computeroutput"
6064 > indicates a full dump,
6065 which has no parent; in this case, the value in the <SAMP
6066 CLASS="computeroutput"
6070 CLASS="computeroutput"
6076 CLASS="computeroutput"
6077 >creation date</SAMP
6081 >The date and time at which the Backup System started the dump operation that created the dump.</P
6085 CLASS="computeroutput"
6090 >For a backup or read-only volume, the time at which it was cloned from its read/write source. For a read/write
6091 volume, the same as the value in the <SAMP
6092 CLASS="computeroutput"
6093 >creation date</SAMP
6098 CLASS="computeroutput"
6103 >The name of the tape containing the dump: either the permanent tape name, or an AFS tape name in the format
6129 > is the name of the volume set associated with the initial dump in the dump set of
6130 which this tape is a part; <SPAN
6136 > is the name of the dump level at which the initial
6137 dump was backed up; <SPAN
6143 > is the ordinal of the tape in the dump set. Either type of name
6144 can be followed by a dump ID in parentheses; if it appears, it is the dump ID of the initial dump in the dump set to
6145 which this appended dump belongs.</P
6151 >The following example shows part of the dump history of the backup volume <SPAN
6155 >user.smith.backup</B
6159 CLASS="programlisting"
6164 >backup volinfo user.smith.backup</B
6167 DumpID lvl parentID creation date clone date tape name
6168 924600000 1 924427600 04/20/1999 05:20 04/20/1999 05:01 user_incr_2 (924514392)
6169 924514392 1 924427600 04/19/1999 05:33 04/19/1999 05:08 user_incr_2
6170 924427600 0 0 04/18/1999 05:26 04/18/1999 04:58 user_full_6
6181 >To scan the contents of a tape</A
6190 >The ability to scan a tape that is corrupted or damaged depends on the extent of the damage and what type of data is
6191 corrupted. The Backup System can almost always scan the tape successfully up to the point of damage. If the damage is minor,
6192 the Backup System can usually skip over it and scan the rest of the tape, but more major damage can prevent further
6193 scanning. A scanning operation does not have to begin with the first tape in a dump set, but the Backup System can process
6194 tapes only in sequential order after the initial tape provided. Therefore, damage on one tape does not prevent scanning of
6195 the others in the dump set, but it is possible to scan either the tapes that precede the damaged one or the ones that follow
6200 >If you use the <SPAN
6206 > flag to scan information into the Backup Database and the first
6207 tape you provide is not the first tape in the dump set, the following restrictions apply: <UL
6210 >If the first data on the tape is a continuation of a volume that begins on the previous (unscanned) tape in the
6211 dump set, the Backup System does not add a record for that volume to the Backup Database.</P
6215 >The Backup System must read the marker that indicates the start of an appended dump to add database records for
6216 the volumes in it. If the first volume on the tape belongs to an appended dump, but is not immediately preceded by the
6217 appended-dump marker, the Backup System does not create a Backup Database record for it or any subsequent volumes that
6218 belong to that appended dump.</P
6225 >Verify that you are authenticated as a user listed in the <SPAN
6229 >/usr/afs/etc/UserList</B
6232 file. If necessary, issue the <SPAN
6238 > command, which is fully described in <A
6239 HREF="c32432.html#HDRWQ593"
6240 >To display the users in the UserList file</A
6242 CLASS="programlisting"
6261 >If the Tape Coordinator for the tape device that is to perform the operation is not already running, open a
6262 connection to the appropriate Tape Coordinator machine and issue the <SPAN
6269 which complete instructions appear in <A
6270 HREF="c15383.html#HDRWQ292"
6271 >To start a Tape Coordinator process</A
6274 CLASS="programlisting"
6299 >If scanning a tape, place it in the drive.</P
6316 interactive mode. <PRE
6317 CLASS="programlisting"
6336 > command to read the contents of the tape.
6338 CLASS="programlisting"
6339 > backup> <SPAN
6368 CLASS="variablelist"
6380 >Is the shortest acceptable abbreviation of <SPAN
6398 >Constructs dump and tape records from the tape and dump labels in the dump and writes them into the Backup
6411 >Specifies the port offset number of the Tape Coordinator process that is handling the operation. You must
6412 provide this argument unless the default value of 0 (zero) is appropriate.</P
6420 >If you did not include the <SPAN
6426 > flag when you issued the <SPAN
6432 > command, or the device's <SPAN
6438 >device_name configuration file
6439 includes the instruction <SPAN
6445 > instruction, then the Tape Coordinator prompts
6446 you to place the tape in the device's drive. You have already done so, but you must now press <<SPAN
6452 >> to indicate that the tape is ready for reading.</P
6457 >To terminate a tape scanning operation, use a termination signal such as <<SPAN
6463 >>, or issue the <SPAN
6469 > command in interactive mode. It
6470 is best not to interrupt the scan if you included the <SPAN
6476 > argument. If the Backup System
6477 has already written new records into the Backup Database, then you must remove them before rerunning the scanning operation.
6478 If during the repeated scan operation the Backup System finds that a record it needs to create already exists, it halts the
6481 >For each dump on the tape, the output in the Tape Coordinator window displays the dump label followed by an entry for
6482 each volume. There is no output in the command window. The dump label has the same fields as the tape label displayed by the
6487 >backup readlabel</B
6489 > command, as described in <A
6490 HREF="c12776.html#HDRWQ272"
6491 >Writing and Reading Tape
6497 >IBM AFS Administration Reference</I
6499 > for a detailed description of the fields in
6502 >The following example shows the dump label and first volume entry on the tape in the device that has port offset
6505 CLASS="programlisting"
6510 >backup scantape 2</B
6514 tape name = monthly_guest
6515 AFS tape name = guests.monthly.3
6516 creationTime = Mon Feb 1 04:06:40 1999
6518 size = 2150000 Kbytes
6519 dump path = /monthly
6522 -- End of dump label --
6524 volume name: user.guest10.backup
6525 volume ID 1937573829
6526 dumpSetName: guests.monthly
6531 clonedate Mon Feb 1 03:03:23 1999
6541 >Restoring and Recovering Data</A
6544 >The purpose of making backups is to enable you to recover when data becomes corrupted or is removed accidentally,
6545 returning the data to a coherent past state. The AFS Backup System provides three commands that restore varying numbers of
6549 >To restore one or more volumes to a single site (partition on an AFS file server machine), use the <SPAN
6553 >backup volrestore</B
6559 >To restore one or more volumes that are defined as a volume set, each to a specified site, use the <SPAN
6563 >backup volsetrestore</B
6569 >To restore an entire partition (that is, all of the volumes that the VLDB lists as resident on it), use the
6574 >backup diskrestore</B
6581 >The commands are suited to different purposes because they vary in the combinations of features they offer and in the
6582 requirements they impose. To decide which is appropriate for a specific restore operation, see the subsequent sections of this
6584 HREF="c15383.html#HDRWQ308"
6585 >Using the backup volrestore Command</A
6587 HREF="c15383.html#HDRWQ310"
6589 diskrestore Command</A
6591 HREF="c15383.html#HDRWQ312"
6592 >Using the backup volsetrestore Command</A
6600 >Making Restore Operations More Efficient</A
6603 >The following comments apply to all types of restore operation: <UL
6606 >The Backup System begins by restoring the most recent full dump of a volume. As it restores subsequent incremental
6607 dumps, it alters the data in the full dump appropriately, essentially repeating the volume's change history. The
6612 >backup diskrestore</B
6618 >backup volsetrestore</B
6621 always restore all incremental dumps, bringing a volume to its state at the time of the most recent incremental dump.
6622 You can use the <SPAN
6626 >backup volrestore</B
6628 > command to return a volume to its state at a
6629 specified time in the past, by not restoring the data from incremental dumps performed after that time.</P
6633 >The Backup System sets a restored volume's creation date to the date and time of the restore operation. The
6634 creation date appears in the <SAMP
6635 CLASS="computeroutput"
6637 > field of the output from the <SPAN
6653 >When identifying the volumes to restore, it is best to specify the base (read/write) name. In this case, the
6654 Backup System searches the Backup Database for the most recent dump set that includes data from either the read/write or
6655 backup version of the volume, and restores dumps of that volume starting with the most recent full dump. If you include
6668 > extension on the volume name,
6669 the Backup System restores dumps of that version only. If it cannot find data dumped from that version, it does not
6670 perform the restoration even if another version was dumped.</P
6674 >All three restoration commands accept the <SPAN
6680 > option, which generates a list of
6681 the volumes to be restored and the tapes or backup data files that contain the necessary dumps, without actually
6682 restoring data to AFS server partitions. This enables you to gather together the tapes before beginning the restore
6683 operation, even preloading them into a stacker or jukebox if you are using one.</P
6687 >If you back up AFS data to tape, restoration is simplest if all of your tape devices are compatible, meaning that
6688 they can read the same type of tape, at the same compression ratios, and so on. (This suggestion also appears in <A
6689 HREF="c15383.html#HDRWQ297"
6690 >Making Backup Operations More Efficient</A
6691 >, because by the time you need to restore data it is
6692 too late to implement it.) You can still restore multiple volumes with a single command even if data was backed up using
6693 incompatible devices, because the <SPAN
6699 > argument to all three restoration
6700 commands accepts multiple values. However, the Backup System uses the first port offset listed when restoring the full
6701 dump of each volume, the next port offset when restoring the level 1 incremental dump of each volume, and so on. If you
6702 did not use a compatible tape device when creating the full dump of every volume (and at each incremental level too),
6703 you cannot restore multiple volumes with a single command. You must use the <SPAN
6710 > command to restore one volume at a time, or use the <SPAN
6717 > command after defining volume sets that group volumes according to the tape device used to dump
6722 >During a restore operation, the Backup System uses instructions in the relevant <SPAN
6728 >device_name configuration file in much the same way as during a dump operation, as described
6730 HREF="c15383.html#HDRWQ298"
6731 >How Your Configuration Choices Influence the Dump Process</A
6732 >. It uses the <SPAN
6763 > instructions just as for a dump
6764 operation. A difference for the <SPAN
6770 > instruction is that the default buffer size
6771 overridden by the instruction is 32 KB for restore operations rather than the 16 KB used for dump operations. The Backup
6772 System does not use the <SPAN
6778 > instruction at all during restore operations. The
6785 > instruction controls whether the Backup System prompts you if it cannot restore a
6786 volume for any reason. If the setting is <SPAN
6792 >, it skips the problematic volume and
6793 restores as many of the other volumes as possible.</P
6797 >Do not perform a restore operation when you know that there are network, machine, or server process problems that
6798 can prevent the Backup System from accessing volumes or the VLDB. Although the Backup System automatically makes a
6799 number of repeated attempts to restore a volume, the restore operation takes extra time and in some cases stops
6800 completely to prompt you for instructions on how to continue.</P
6804 >Avoid halting a restore operation (for instance by issuing the <SPAN
6811 command in interactive mode). If a restore operation is interrupted for any reason, including causes outside your
6812 control, reissue the same restoration command as soon as is practical; if an outage or other problem caused the
6813 operation to halt, do not continue until the system returns to normal.</P
6815 >Any volume that is completely restored when the operation halts is online and usable, but very few volumes are
6816 likely to be in this state. When restoring multiple volumes at once, the Backup System restores the full dump of every
6817 volume before beginning the level 1 incremental restore for any of them, and so on, completing the restore of every
6818 volume at a specific incremental level before beginning to restore data from the next incremental level. Unless a volume
6819 was dumped at fewer incremental levels than others being restored as part of the same operation, it is unlikely to be
6822 >It is even more dangerous to interrupt a restore operation if you are overwriting the current contents of the
6823 volume. Depending on how far the restore operation has progressed, it is possible that the volume is in such an
6824 inconsistent state that the Backup System removes it entirely. The data being restored is still available on tape or in
6825 the backup data file, but you must take extra steps to re-create the volume.</P
6836 >Using the backup volrestore Command</A
6843 >backup volrestore</B
6845 > command is most appropriate when you need to restore a few
6846 volumes to a single site (partition on a file server machine). By default, it restores the volumes to their state at the time
6847 of the most recent dump operation (this is termed a <SPAN
6853 >). You can also use the command to
6858 >date-specific restore</I
6860 >, which restores only the dumps (full and incremental) performed before a
6861 specified date and time, leaving the volume in the state it was in at the time of the final relevant incremental dump. The
6866 >backup diskrestore</B
6872 >backup volsetrestore</B
6875 only perform full restores.</P
6877 >You can restore data into a new copy of each volume rather than overwriting the current version, by including the
6884 > argument. After mounting the new volume in the filespace, you can compare the
6885 contents of the two and decide which to keep permanently.</P
6887 >The following list summarizes how to combine the <SPAN
6891 >backup volrestore</B
6893 > command's arguments
6894 to restore a volume in different ways: <UL
6897 >To perform a date-specific restore as described just previously, use the <SPAN
6904 argument to specify the date and optionally time. The Backup System restores the most recent full dump and each
6905 subsequent incremental dump for which the clone date of the volume included in the dump is before the indicated date and
6906 time (for a definition of the clone date, see Step <A
6907 HREF="c15383.html#LIBKOV-CLONEDATE"
6910 HREF="c15383.html#HDRWQ298"
6911 >How Your Configuration Choices Influence the Dump Process</A
6912 >). You can combine this argument with
6919 > argument to place the date-specific restore in a new volume.</P
6923 >To move a volume to a new site as you overwrite its contents with the restored data, use the <SPAN
6935 > arguments, singly or in combination, to
6936 specify the new site rather than the current site. The Backup System creates a new volume at that site, removes the
6937 existing volume, and updates the site information in the volume's VLDB entry. The volume's backup version is not removed
6938 automatically from the original site, if it exists. Use the <SPAN
6945 remove it and the <SPAN
6951 > command to create a backup version at the new site.</P
6955 >To create a new volume to house the restored data, rather than overwriting an existing volume, use the <SPAN
6961 > argument. The Backup System creates the new volume on the server and partition named
6974 > arguments, derives its
6975 name by adding the extension to the name specified with the <SPAN
6982 creates a new VLDB entry for it. The command does not affect the existing volume in any way. However, if a volume with
6983 the specified extension also already exists, the command overwrites it. To make the contents of the new volume
6984 accessible, use the <SPAN
6990 > command to mount it. You can then compare its contents
6991 to those of the existing volume, to see which to retain permanently.</P
6995 >To restore a volume that no longer exists on an AFS server partition, but for which you have backed up data,
6996 specify the name of the new volume with the <SPAN
7002 > argument and use the <SPAN
7014 > arguments to place it at the desired
7015 site. The Backup System creates a new volume and new VLDB entry.</P
7026 >To restore volumes with the backup volrestore command</A
7032 >Verify that you are authenticated as a user listed in the <SPAN
7036 >/usr/afs/etc/UserList</B
7039 file. If necessary, issue the <SPAN
7045 > command, which is fully described in <A
7046 HREF="c32432.html#HDRWQ593"
7047 >To display the users in the UserList file</A
7049 CLASS="programlisting"
7068 >If the Tape Coordinator for the tape device that is to perform the operation is not already running, open a
7069 connection to the appropriate Tape Coordinator machine and issue the <SPAN
7076 which complete instructions appear in <A
7077 HREF="c15383.html#HDRWQ292"
7078 >To start a Tape Coordinator process</A
7081 CLASS="programlisting"
7104 >Repeat the command for each Tape Coordinator if you are using more than one tape device.</P
7108 >If using a tape device, insert the tape.</P
7118 > command to enter interactive mode. <PRE
7119 CLASS="programlisting"
7136 >backup volrestore</B
7138 > command with the desired arguments. <PRE
7139 CLASS="programlisting"
7140 > backup> <SPAN
7150 >destination machine</I
7156 >destination partition</I
7169 >volume(s) to restore</I
7182 >new volume name extension</I
7195 >date from which to restore</I
7221 CLASS="variablelist"
7233 >Is the shortest acceptable abbreviation of <SPAN
7246 >destination machine</B
7251 >Names the file server machine on which to restore each volume. It does not have to be a volume's current
7259 >destination partition</B
7264 >Names the partition on which to restore each volume. It does not have to be a volume's current site.</P
7276 >Names each volume to restore. It is best to provide the base (read/write) name, for the reasons discussed in
7278 HREF="c15383.html#HDRWQ307"
7279 >Making Restore Operations More Efficient</A
7292 >Creates a new volume to house the restored data, with a name derived by appending the specified string to
7293 each volume named by the <SPAN
7299 > extension. The Backup System preserves the
7300 contents of the existing volume if it still exists. Do not use either of the <SPAN
7312 > extensions, which are reserved. The
7313 combination of base volume name and extension cannot exceed 22 characters in length. If you want a period to
7314 separate the extension from the name, specify it as the first character of the string (as in <SPAN
7332 >Specifies a date and optionally time; the restored volume includes data from dumps performed before the date
7333 only. Provide a value in the format mm/dd/yyyy [hh:MM], where the required mm/dd/yyyy portion indicates the month
7334 (mm), day (dd), and year (yyyy), and the optional hh:MM portion indicates the hour and minutes in 24-hour format
7335 (for example, the value <SPAN
7341 > represents 2:36 p.m.). If omitted, the time
7342 defaults to 59 seconds after midnight (00:00:59 hours).</P
7344 >Valid values for the year range from <SPAN
7356 >; higher values are not valid because the latest possible date in the standard UNIX
7357 representation is in February 2038. The command interpreter automatically reduces any later date to the maximum
7366 >A plus sign follows this argument in the command's syntax statement because it accepts a multiword value
7367 which does not need to be enclosed in double quotes or other delimiters, not because it accepts multiple dates.
7368 Provide only one date (and optionally, time) definition.</P
7382 >Specifies one or more port offset numbers, each corresponding to a Tape Coordinator to use in the operation.
7383 If there is more than one value, the Backup System uses the first one when restoring the full dump of each volume,
7384 the second one when restoring the level 1 incremental dump of each volume, and so on. It uses the final value in
7385 the list when restoring dumps at the corresponding depth in the dump hierarchy and all dumps at lower
7388 >Provide this argument unless the default value of 0 (zero) is appropriate for all dumps. If 0 is just one of
7389 the values in the list, provide it explicitly in the appropriate order.</P
7401 >Displays the list of tapes that contain the dumps required by the restore operation, without actually
7402 performing the operation.</P
7410 >If you did not include the <SPAN
7416 > flag when you issued the <SPAN
7422 > command, or the device's <SPAN
7428 >device_name configuration file
7429 includes the instruction <SPAN
7435 >, then the Tape Coordinator prompts you to place
7436 the tape in the device's drive. You have already done so, but you must now press <<SPAN
7442 >> to indicate that the tape is ready for labeling.</P
7444 >If more than one tape is required, you must either include the <SPAN
7457 >device_name file and stock the corresponding stacker or jukebox with tapes, or
7458 remain at the console to respond to the Tape Coordinator's prompts for subsequent tapes.</P
7462 >After the restore operation completes, review the Backup System's log files to check for errors. Use the <SPAN
7468 > command as instructed in <A
7469 HREF="c6449.html#HDRWQ173"
7470 >Displaying Server Process Log
7476 >/usr/afs/logs/BackupLog</B
7478 > file, and a text editor on the Tape
7479 Coordinator machine to read the <SPAN
7485 >device_name and <SPAN
7491 >device_name files in the local <SPAN
7508 >Using the backup diskrestore Command</A
7515 >backup diskrestore</B
7517 > command is most appropriate when you need to restore all of the
7518 volumes on an AFS server partition, perhaps because a hardware failure has corrupted or destroyed all of the data. The command
7519 performs a full restore of all of the read/write volumes for which the VLDB lists the specified partition as the current site,
7520 using the dumps of either the read/write or backup version of each volume depending on which type was dumped more recently.
7521 (You can restore any backup or read-only volumes that resided on the partition by using the <SPAN
7534 > commands after the <SPAN
7541 > operation is complete.)</P
7543 >By default, the Backup System restores the volumes to the site they previously occupied. To move the partition contents
7544 to a different site, use the <SPAN
7557 arguments, singly or in combination.</P
7559 >By default, the Backup System overwrites the contents of existing volumes with the restored data. To create a new volume
7560 to house the restored data instead, use the <SPAN
7566 > argument. The Backup System creates
7567 the new volume at the site designated by the <SPAN
7579 > arguments if they are used or the <SPAN
7591 > arguments otherwise. It derives the volume name by adding the extension to the read/write
7592 base name listed in the VLDB, and creates a new VLDB entry. The command does not affect the existing volume in any way.
7593 However, if a volume with the specified extension also already exists, the command overwrites it.</P
7595 >If a partition seems damaged, be sure not to run the <SPAN
7601 > command before the
7606 >backup diskrestore</B
7608 > command. As noted, the Backup System restores volumes according to VLDB
7609 site definitions. The <SPAN
7615 > command sometimes removes a volume's VLDB entry when the
7616 corruption on the partition is so severe that the Volume Server cannot confirm the volume's presence.</P
7624 >To restore a partition with the backup diskrestore command</A
7630 >Verify that you are authenticated as a user listed in the <SPAN
7634 >/usr/afs/etc/UserList</B
7637 file. If necessary, issue the <SPAN
7643 > command, which is fully described in <A
7644 HREF="c32432.html#HDRWQ593"
7645 >To display the users in the UserList file</A
7647 CLASS="programlisting"
7666 >If the Tape Coordinator for the tape device that is to perform the operation is not already running, open a
7667 connection to the appropriate Tape Coordinator machine and issue the <SPAN
7674 which complete instructions appear in <A
7675 HREF="c15383.html#HDRWQ292"
7676 >To start a Tape Coordinator process</A
7679 CLASS="programlisting"
7702 >Repeat the command for each Tape Coordinator if you are using more than one tape device.</P
7706 >If using a tape device, insert the tape.</P
7716 > command to enter interactive mode. <PRE
7717 CLASS="programlisting"
7734 >backup diskrestore</B
7736 > command with the desired arguments. <PRE
7737 CLASS="programlisting"
7738 > backup> <SPAN
7748 >machine to restore</I
7754 >partition to restore</I
7780 >destination machine</I
7793 >destination partition</I
7806 >new volume name extension</I
7819 CLASS="variablelist"
7831 >Is the shortest acceptable abbreviation of <SPAN
7844 >machine to restore</B
7849 >Names the file server machine that the VLDB lists as the site of the volumes that need to be
7857 >partition to restore</B
7862 >Names the partition that the VLDB lists as the site of the volumes that need to be restored.</P
7874 >Specifies one or more port offset numbers, each corresponding to a Tape Coordinator to use in the operation.
7875 If there is more than one value, the Backup System uses the first one when restoring the full dump of each volume,
7876 the second one when restoring the level 1 incremental dump of each volume, and so on. It uses the final value in
7877 the list when restoring dumps at the corresponding depth in the dump hierarchy and all dumps at lower
7880 >Provide this argument unless the default value of 0 (zero) is appropriate for all dumps. If 0 is just one of
7881 the values in the list, provide it explicitly in the appropriate order.</P
7893 >Names an alternate file server machine to which to restore the volumes. If you omit this argument, the
7894 volumes are restored to the file server machine named by the <SPAN
7913 >Names an alternate partition to which to restore the data. If you omit this argument, the volumes are
7914 restored to the partition named by the <SPAN
7932 >Creates a new volume for each volume being restored, to house the restored data, appending the specified
7933 string to the volume's read/write base name as listed in the VLDB. Any string other than <SPAN
7945 > is acceptable, but the combination of
7946 the base name and extension cannot exceed 22 characters in length. To use a period to separate the extension from
7947 the name, specify it as the first character of the string (as in <SPAN
7966 >Displays a list of the tapes necessary to perform the requested restore, without actually performing the
7975 >If you did not include the <SPAN
7981 > flag when you issued the <SPAN
7987 > command, or the device's <SPAN
7993 >device_name configuration file
7994 includes the instruction <SPAN
8000 >, then the Tape Coordinator prompts you to place
8001 the tape in the device's drive. You have already done so, but you must now press <<SPAN
8007 >> to indicate that the tape is ready for labeling.</P
8009 >If more than one tape is required, you must either include the <SPAN
8022 >device_name file and stock the corresponding stacker or jukebox with tapes, or
8023 remain at the console to respond to the Tape Coordinator's prompts for subsequent tapes.</P
8027 >After the restore operation completes, review the Backup System's log files to check for errors. Use the <SPAN
8033 > command as instructed in <A
8034 HREF="c6449.html#HDRWQ173"
8035 >Displaying Server Process Log
8041 >/usr/afs/logs/BackupLog</B
8043 > file, and a text editor on the Tape
8044 Coordinator machine to read the <SPAN
8050 >device_name and <SPAN
8056 >device_name files in the local <SPAN
8073 >Using the backup volsetrestore Command</A
8080 >backup volsetrestore</B
8082 > command is most appropriate when you need to perform a full
8083 restore of several read/write volumes, placing each at a specified site. You specify the volumes to restore either by naming a
8084 volume set with the <SPAN
8090 > argument or by listing each volume's name and restoration site in a
8091 file named by the <SPAN
8097 > argument, as described in the following sections.</P
8103 >backup volsetrestore</B
8105 > command enables you to restore a large number of
8106 volumes with a single command, the restore operation can potentially take hours to complete. One way to reduce the time is to
8107 run multiple instances of the command simultaneously. Either use the <SPAN
8114 specify disjoint volume sets for each command, or the <SPAN
8120 > argument to name files that list
8121 different volumes. You must have several Tape Coordinators available to read the required tapes. Depending on how the volumes
8122 to be restored were dumped to tape, specifying disjoint volume sets can also reduce the number of tape changes
8130 >Restoring a Volume Set with the -name Argument</A
8139 > argument to restore a group of volumes defined in a volume set. The
8140 Backup System creates a list of the volumes in the VLDB that match the server, partition, and volume name criteria defined
8141 in the volume set's volume entries, and for which dumps are available. The volumes do not have to exist on the server
8142 partition as long as the VLDB still lists them (this can happen when, for instance, a hardware problem destroys the contents
8143 of an entire disk).</P
8145 >By default, the Backup System restores, as a read/write volume, each volume that matches the volume set criteria to
8146 the site listed in the VLDB. If a volume of the matching name exists at that site, its current contents are overwritten. You
8147 can instead create a new volume to house the restored data by including the <SPAN
8154 argument. The Backup System creates the new volume at the existing volume's site, derives its name by adding the extension
8155 to the existing volume's read/write base name, and creates a new VLDB entry for it. The command does not affect the existing
8156 volume in any way. However, if a volume with the specified extension also already exists, the command overwrites it. To make
8157 the contents of the new volume accessible, use the <SPAN
8163 > command to mount it. You can
8164 then compare its contents to those of the existing volume, to see which to retain permanently.</P
8166 >It is not required that the volume set was previously used to back up volumes (was used as the <SPAN
8172 > option to the <SPAN
8178 > command). It can be defined
8179 especially to match the volumes that need to be restored with this command, and that is usually the better choice. Indeed, a
8186 > volume set, created by including the <SPAN
8197 >backup addvolset</B
8199 > command, can be especially useful in this context (instructions appear in
8201 HREF="c12776.html#HDRWQ265"
8202 >Defining and Displaying Volume Sets and Volume Entries</A
8203 >). A temporary volume set is not added
8204 to the Backup Database and exists only during the current interactive backup session, which is suitable if the volume set is
8205 needed only to complete the single restore operation initialized by this command.</P
8207 >The reason that a specially defined volume set is probably better is that volume sets previously defined for use in
8208 dump operations usually match the backup version of volumes, whereas for a restore operation it is best to define volume
8209 entries that match the base (read/write) name. In this case, the Backup System searches the Backup Database for the newest
8210 dump set that includes a dump of either the read/write or the backup version of the volume. If, in contrast, a volume entry
8211 explicitly matches the volume's backup or read-only version, the Backup System uses dumps of that volume version only,
8212 restoring them to a read/write volume by stripping off the <SPAN
8226 >If there are VLDB entries that match the volume set criteria, but for which there are no dumps recorded in the Backup
8227 Database, the Backup System cannot restore them. It generates an error message on the standard error stream for each
8236 >Restoring Volumes Listed in a File with the -file Argument</A
8245 > argument to specify the name and site of each read/write volume to
8246 restore. Each volume's entry must appear on its own (unbroken) line in the file, and comply with the following
8249 CLASS="programlisting"
8250 > machine partition volume [comments...]
8254 CLASS="variablelist"
8266 >Names the file server machine to which to restore the volume. You can move the volume as you restore it by
8267 naming a machine other than the current site.</P
8279 >Names the partition to which to restore the volume. You can move the volume as you restore it by naming a
8280 partition other than the current site.</P
8292 >Names the volume to restore. Specify the base (read/write) name to have the Backup System search the Backup
8293 Database for the newest dump set that includes a dump of either the read/write or the backup version of the volume.
8294 It restores the dumps of that version of the volume, starting with the most recent full dump. If, in contrast, you
8296 CLASS="computeroutput"
8299 CLASS="computeroutput"
8302 Backup System restores dumps of that volume version only, but into a read/write volume without the extension. The
8303 base name must match the name used in Backup Database dump records rather than in the VLDB, if they differ, because
8304 the Backup System does not consult the VLDB when you use the <SPAN
8322 >Is any other text. The Backup System ignores any text on each line that appears after the volume name, so you
8323 can use this field for helpful notes.</P
8329 >Do not use wildcards (for example, <SPAN
8335 >) in the machine, partition, or volume fields.
8336 It is acceptable for multiple lines in the file to name the same volume, but the Backup System processes only the first of
8339 >By default, the Backup System replaces the existing version of each volume with the restored data, placing the volume
8340 at the site specified in the machine and partition fields. You can instead create a new volume to house the restored
8341 contents by including the <SPAN
8347 > argument. The Backup System creates a new volume at
8348 the site named in the machine and partition fields, derives its name by adding the specified extension to the read/write
8349 version of the name in the volume field, and creates a new VLDB entry for it. The command does not affect the existing
8350 volume in any way. However, if a volume with the specified extension also already exists, the command overwrites it. To make
8351 the contents of the new volume accessible, use the <SPAN
8357 > command to mount it. You can
8358 then compare its contents to those of the existing volume, to see which to retain permanently.</P
8360 >If the file includes entries for volumes that have no dumps recorded in the Backup Database, the Backup System cannot
8361 restore them. It generates an error message on the standard error stream for each one.</P
8363 >One way to generate a file to use as input to the <SPAN
8369 > argument is to issue the
8370 command with the <SPAN
8382 > options and direct the
8383 output to a file. The output includes a line like the following for each volume (shown here on two lines only for legibility
8384 reasons); the value comes from the source indicated in the following list:</P
8386 CLASS="programlisting"
8387 > machine partition volume_dumped # as volume_restored; \
8388 tape_name (tape_ID); pos position_number; date
8392 CLASS="variablelist"
8404 >Names the file server machine that currently houses the volume, as listed in the VLDB.</P
8416 >Names the partition that currently houses the volume, as listed in the VLDB.</P
8428 >Specifies the version (read/write or backup) of the volume that was dumped, as listed in the Backup
8441 >Specifies the name under which the Backup System restores the volume when the <SPAN
8447 > flag is not included. If you include the <SPAN
8454 argument with the <SPAN
8467 extension appears on the name in this field (as in <SAMP
8468 CLASS="computeroutput"
8483 >Names the tape containing the dump of the volume, from the Backup Database. If the tape has a permanent name,
8484 it appears here; otherwise, it is the AFS tape name.</P
8496 >The tape ID of the tape containing the dump of the volume, from the Backup Database.</P
8508 >Specifies the dump's position on the tape (for example, <SAMP
8509 CLASS="computeroutput"
8512 volume dumps precede the current one on the tape). If the dump was written to a backup data file, this number is the
8513 ordinal of the 16 KB-offset at which the volume's data begins.</P
8525 >The date and time when the volume was dumped.</P
8531 >To make the entries suitable for use with the <SPAN
8537 > argument, edit them as indicated:
8541 >The Backup System uses only the first three fields on each line of the input file, and so ignores all the fields
8542 after the number sign (<SAMP
8543 CLASS="computeroutput"
8545 >). You can remove them if it makes it easier for you to read
8546 the file, but that is not necessary.</P
8550 >The volume_dumped (third) field of each line in the output file becomes the volume field in the input file. The
8551 Backup System restores data to read/write volumes only, so remove the <SAMP
8552 CLASS="computeroutput"
8556 CLASS="computeroutput"
8558 > extension if it appears on the name in the volume_dumped field.</P
8562 >The output file includes a line for every dump operation in which a specific volume was included (the full dump
8563 and any incremental dumps), but the Backup System only processes the first line in the input file that mentions a
8564 specific volume. You can remove the repeated lines if it makes the file easier for you to read.</P
8580 > fields on an output line designate the
8581 volume's current site. To move the volume to another location as you restore it, change the values.</P
8593 >To restore a group of volumes with the backup volsetrestore command</A
8599 >Verify that you are authenticated as a user listed in the <SPAN
8603 >/usr/afs/etc/UserList</B
8606 file. If necessary, issue the <SPAN
8612 > command, which is fully described in <A
8613 HREF="c32432.html#HDRWQ593"
8614 >To display the users in the UserList file</A
8616 CLASS="programlisting"
8635 >If the Tape Coordinator for the tape device that is to perform the operation is not already running, open a
8636 connection to the appropriate Tape Coordinator machine and issue the <SPAN
8643 which complete instructions appear in <A
8644 HREF="c15383.html#HDRWQ292"
8645 >To start a Tape Coordinator process</A
8648 CLASS="programlisting"
8671 >Repeat the command for each Tape Coordinator if you are using more than one tape device.</P
8675 >If using a tape device, insert the tape.</P
8685 > command to enter interactive mode. <PRE
8686 CLASS="programlisting"
8705 > If appropriate, issue the <SPAN
8712 > command to create a new volume set expressly for this restore operation. Include the <SPAN
8718 > flag if you do not need to add the volume set to the Backup Database. Then issue one or
8723 >(backup) addvolentry</B
8725 > commands to create volume entries that include only the volumes
8726 to be restored. Complete instructions appear in <A
8727 HREF="c12776.html#HDRWQ265"
8728 >Defining and Displaying Volume Sets and Volume
8731 CLASS="programlisting"
8732 > backup> <SPAN
8755 >addvolentry -name</B
8800 >volume name (regular expression)</I
8812 >backup volsetrestore</B
8814 > command with the desired arguments. <PRE
8815 CLASS="programlisting"
8816 > backup> <SPAN
8871 >new volume name extension</I
8884 CLASS="variablelist"
8896 >Names a volume set to restore. The Backup System restores all of the volumes listed in the VLDB that match
8897 the volume set's volume entries, as described in <A
8898 HREF="c15383.html#HDRWQ313"
8899 >Restoring a Volume Set with the -name
8901 >. Provide this argument or the <SPAN
8920 >Specifies the full pathname of a file that lists one or more volumes and the site (file server machine and
8921 partition) to which to restore each. The input file has the format described in <A
8922 HREF="c15383.html#HDRWQ314"
8924 Volumes Listed in a File with the -file Argument</A
8925 >. Use either this argument or the <SPAN
8931 > argument, but not both.</P
8943 >Specifies one or more port offset numbers, each corresponding to a Tape Coordinator to use in the operation.
8944 If there is more than one value, the Backup System uses the first one when restoring the full dump of each volume,
8945 the second one when restoring the level 1 incremental dump of each volume, and so on. It uses the final value in
8946 the list when restoring dumps at the corresponding depth in the dump hierarchy and all dumps at lower
8949 >Provide this argument unless the default value of 0 (zero) is appropriate for all dumps. If 0 is just one of
8950 the values in the list, provide it explicitly in the appropriate order.</P
8962 >Creates a new volume for each volume being restored, to house the restored data, appending the specified
8963 string to the volume's read/write base name as listed in the VLDB. Any string other than <SPAN
8975 > is acceptable, but the combination of
8976 the base name and extension cannot exceed 22 characters in length. To use a period to separate the extension from
8977 the name, specify it as the first character of the string (as in <SPAN
8996 >Displays a list of the volumes to be restored when the flag is not included, without actually restoring
9003 > section of this reference page details the format of the output.
9004 When combined with the <SPAN
9010 > argument, its output is easily edited for use as
9017 > argument on a subsequent <SPAN
9032 >If you did not include the <SPAN
9038 > flag when you issued the <SPAN
9044 > command, or the device's <SPAN
9050 >device_name configuration file
9051 includes the instruction <SPAN
9057 >, then the Tape Coordinator prompts you to place
9058 the tape in the device's drive. You have already done so, but you must now press <<SPAN
9064 >> to indicate that the tape is ready for labeling.</P
9066 >If more than one tape is required, you must either include the <SPAN
9079 >device_name file and stock the corresponding stacker or jukebox with tapes, or
9080 remain at the console to respond to the Tape Coordinator's prompts for subsequent tapes.</P
9084 >After the restore operation completes, review the Backup System's log files to check for errors. Use the <SPAN
9090 > command as instructed in <A
9091 HREF="c6449.html#HDRWQ173"
9092 >Displaying Server Process Log
9098 >/usr/afs/logs/BackupLog</B
9100 > file, and a text editor on the Tape
9101 Coordinator machine to read the <SPAN
9107 >device_name and <SPAN
9113 >device_name files in the local <SPAN
9131 >Maintaining the Backup Database</A
9134 >The Backup Database stores all of the configuration and tracking information that the Backup System uses when dumping and
9135 restoring data. If a hardware failure or other problem on a database server machine corrupts or damages the database, it is
9136 relatively easy to recreate the configuration information (the dump hierarchy and lists of volume sets and Tape Coordinator port
9137 offset numbers). However, restoring the dump tracking information (dump records) is more complicated and time-consuming. To
9138 protect yourself against loss of data, back up the Backup Database itself to tape on a regular schedule.</P
9140 >Another potential concern is that the Backup Database can grow large rather quickly, because the Backup System keeps very
9141 detailed and cross-referenced records of dump operations. Backup operations become less efficient if the Backup Server has to
9142 navigate through a large number of obsolete records to find the data it needs. To keep the database to a manageable size, use
9147 >backup deletedump</B
9149 > command to delete obsolete records, as described in <A
9150 HREF="c15383.html#HDRWQ321"
9151 >Removing Obsolete Records from the Backup Database</A
9152 >. If you later find that you have removed records
9153 that you still need, you can use the <SPAN
9159 > command to read the information from the
9160 dump and tape labels on the corresponding tapes back into the database, as instructed in <A
9161 HREF="c15383.html#HDRWQ305"
9163 contents of a tape</A
9171 >Backing Up and Restoring the Backup Database</A
9174 >Because of the importance of the information in the Backup Database, it is best to back it up to tape or other permanent
9175 media on a regular basis. As for the other AFS, administrative databases, the recommended method is to use a utility designed
9176 to back up a machine's local disk, such as the UNIX <SPAN
9182 > command. For instructions, see <A
9183 HREF="c3025.html#HDRWQ107"
9184 >Backing Up and Restoring the Administrative Databases</A
9187 >In the rare event that the Backup Database seems damaged or corrupted, you can use the <SPAN
9194 > command to check its status. If it is corrupted, use the <SPAN
9201 command to repair some types of damage. Then use the <SPAN
9205 >backup restoredb</B
9207 > to return the corrected
9208 database to the local disks of the database server machines. For instructions, see <A
9209 HREF="c15383.html#HDRWQ318"
9211 Repairing Corruption in the Backup Database</A
9220 >Checking for and Repairing Corruption in the Backup Database</A
9223 >In rare cases, the Backup Database can become damaged or corrupted, perhaps because of disk or other hardware errors.
9230 > command to check the integrity of the database. If it is corrupted,
9231 the most efficient way to repair it is to use the <SPAN
9237 > command to copy the database
9238 to tape. The command automatically repairs several types of corruption, and you can then use the <SPAN
9245 > command to transfer the repaired copy of the database back to the local disks of the database server
9254 > command also removes <SPAN
9261 ranges of memory that the Backup Server preallocated in the database but cannot use. Orphan blocks do not interfere with
9262 database access, but do waste disk space. The <SPAN
9268 > command reports the existence
9269 of orphan blocks if you include the <SPAN
9283 >To verify the integrity of the Backup Database</A
9289 >Verify that you are authenticated as a user listed in the <SPAN
9293 >/usr/afs/etc/UserList</B
9296 file. If necessary, issue the <SPAN
9302 > command, which is fully described in <A
9303 HREF="c32432.html#HDRWQ593"
9304 >To display the users in the UserList file</A
9306 CLASS="programlisting"
9331 > command to check the integrity of the Backup Database.
9333 CLASS="programlisting"
9351 CLASS="variablelist"
9363 >Is the shortest acceptable abbreviation of <SPAN
9381 >Reports the existence of orphan blocks and other information about the database, as described on the
9388 > reference page in the <SPAN
9392 >IBM AFS Administration
9401 >The output reports one of the following messages: <UL
9405 CLASS="computeroutput"
9407 > indicates that the Backup Database is undamaged.</P
9412 CLASS="computeroutput"
9413 >Database not OK</SAMP
9414 > indicates that the Backup Database is damaged. To recover
9415 from the problem, use the instructions in <A
9416 HREF="c15383.html#HDRWQ320"
9417 >To repair corruption in the Backup
9432 >To repair corruption in the Backup Database</A
9438 >Log in as the local superuser <SPAN
9444 > on each database server machine in the
9450 NAME="LISAVEDB-STARTTC"
9452 >If the Tape Coordinator for the tape device that is to perform the operation is not
9453 already running, open a connection to the appropriate Tape Coordinator machine and issue the <SPAN
9459 > command, for which complete instructions appear in <A
9460 HREF="c15383.html#HDRWQ292"
9462 Coordinator process</A
9464 CLASS="programlisting"
9489 >If writing to tape, place a tape in the appropriate device.</P
9493 >Working on one of the machines, issue the <SPAN
9499 > command to enter interactive mode.
9501 CLASS="programlisting"
9506 >backup -localauth</B
9518 > constructs a server ticket from the local <SPAN
9522 >/usr/afs/etc/KeyFile</B
9524 > file. This flag enables you to issue a privileged command while logged in as
9525 the local superuser <SPAN
9531 > but without AFS administrative tokens.</P
9535 >Verify that no backup operations are actively running. If necessary, issue the <SPAN
9542 > command as described in <A
9543 HREF="c15383.html#HDRWQ295"
9544 >To check the status of a Tape Coordinator
9546 >. Repeat for each Tape Coordinator port offset in turn. <PRE
9547 CLASS="programlisting"
9548 > backup> <SPAN
9552 >status -portoffset</B
9575 > command to repair corruption
9576 in the database as it is written to tape or a file. <PRE
9577 CLASS="programlisting"
9578 > backup> <SPAN
9601 CLASS="variablelist"
9613 >Is the shortest acceptable abbreviation of <SPAN
9631 >Specifies the port offset number of the Tape Coordinator handling the tape or backup data file for this
9632 operation. You must provide this argument unless the default value of 0 (zero) is appropriate.</P
9640 >Exit interactive mode. <PRE
9641 CLASS="programlisting"
9642 > backup> <SPAN
9654 >On each machine in turn, issue the <SPAN
9660 > command to shut down the Backup
9661 Server process. Include the <SPAN
9667 > flag because you are logged in as the local
9668 superuser root, but do not necessarily have administrative tokens. For complete command syntax, see <A
9669 HREF="c6449.html#HDRWQ168"
9670 >To stop processes temporarily</A
9672 CLASS="programlisting"
9677 >/usr/afs/bin/bos shutdown</B
9689 >buserver -localauth -wait</B
9697 >On each machine in turn, issue the following commands to remove the Backup Database. <PRE
9698 CLASS="programlisting"
9725 >On each machine in turn, starting with the machine with the lowest IP address, issue the <SPAN
9732 > command to restart the Backup Server process, which creates a zero-length copy of the Backup Database as
9733 it starts. For complete command syntax, see <A
9734 HREF="c6449.html#HDRWQ166"
9735 >To start processes by changing their status flags to
9738 CLASS="programlisting"
9743 >/usr/afs/bin/bos start</B
9755 >buserver -localauth</B
9763 >Working on one of the machines, issue the <SPAN
9769 > command to enter interactive mode.
9771 CLASS="programlisting"
9776 >backup -localauth</B
9788 > constructs a server ticket from the local <SPAN
9792 >/usr/afs/etc/KeyFile</B
9802 >(backup) addhost</B
9804 > command to create an entry in the new, empty database
9805 for the Tape Coordinator process handling the tape or file from which you are reading the repaired copy of the database
9806 (presumably the process you started in Step <A
9807 HREF="c15383.html#LISAVEDB-STARTTC"
9809 > and which performed the <SPAN
9815 > operation in Step <A
9816 HREF="c15383.html#LISAVEDB-CMD"
9818 >). For complete syntax, see
9820 HREF="c12776.html#LICONFTC-ADDHOST"
9823 HREF="c12776.html#HDRWQ262"
9824 >To configure a Tape Coordinator machine</A
9827 CLASS="programlisting"
9828 > backup> <SPAN
9838 >tape machine name</I
9856 >(backup) restoredb</B
9858 > command to copy the repaired database to the database
9859 server machines. <PRE
9860 CLASS="programlisting"
9861 > backup> <SPAN
9884 CLASS="variablelist"
9896 >Is the shortest acceptable abbreviation of <SPAN
9914 >Specifies the port offset number of the Tape Coordinator handling the tape or backup data file for this
9915 operation. You must provide this argument unless the default value of <SPAN
9936 > Exit interactive mode if you do not plan to issue any additional
9944 CLASS="programlisting"
9945 > backup> <SPAN
9963 > If desired, enter <SPAN
9970 interrupt signal to exit the <SPAN
9976 > shell on each database server machine. You can also
9983 > signal on the Tape Coordinator machine to stop the process.</P
9993 >Removing Obsolete Records from the Backup Database</A
9996 >Whenever you recycle or relabel a tape using the <SPAN
10006 >backup labeltape</B
10008 > command, the Backup System automatically removes all of the dump records for the dumps
10009 contained on the tape and all other tapes in the dump set. However, obsolete records can still accumulate in the Backup
10010 Database over time. For example, when you discard a backup tape after using it the maximum number of times recommended by the
10011 manufacturer, the records for dumps on it remain in the database. Similarly, the Backup System does not automatically remove a
10012 dump's record when the dump reaches its expiration date, but only if you then recycle or relabel the tape that contains the
10013 dump. Finally, if a backup operation halts in the middle, the records for any volumes successfully written to tape before the
10014 halt remain in the database.</P
10016 >A very large Backup Database can make backup operations less efficient because the Backup Server has to navigate through
10017 a large number of records to find the ones it needs. To remove obsolete records, use the <SPAN
10024 > command. Either identify individual dumps by dump ID number, or specify the removal of all dumps created
10025 during a certain time period. Keep in mind that you cannot remove the record of an appended dump except by removing the record
10026 of its initial dump, which removes the records of all associated appended dumps. Removing records of a dump makes it
10027 impossible to restore data from the corresponding tapes or from any dump that refers to the deleted dump as its parent,
10028 directly or indirectly. That is, restore operations must begin with the full dump and continue with each incremental dump in
10029 order. If you have removed the records for a specific dump, you cannot restore any data from later incremental dumps.</P
10031 >Another way to truncate the Backup Database is to include the <SPAN
10044 > command. After a copy of the database is written to tape or to a backup data
10045 file, the Backup Server deletes the dump records for all dump operations with timestamps prior to the date and time you
10046 specify. However, issuing the <SPAN
10050 >backup deletedump</B
10052 > command with only the <SPAN
10058 > argument is equivalent in effect and is simpler because it does not require starting a Tape
10059 Coordinator process as the <SPAN
10065 > command does. For further information on the
10072 > argument to the <SPAN
10079 command's reference page in the <SPAN
10083 >IBM AFS Administration Reference</I
10087 >If you later need to access deleted dump records, and the corresponding tapes still exist, you can use the <SPAN
10093 > argument to the <SPAN
10097 >backup scantape</B
10099 > command to scan their contents
10100 into the database, as instructed in <A
10101 HREF="c15383.html#HDRWQ305"
10102 >To scan the contents of a tape</A
10111 >To delete dump records from the Backup Database</A
10117 >Verify that you are authenticated as a user listed in the <SPAN
10121 >/usr/afs/etc/UserList</B
10124 file. If necessary, issue the <SPAN
10130 > command, which is fully described in <A
10131 HREF="c32432.html#HDRWQ593"
10132 >To display the users in the UserList file</A
10134 CLASS="programlisting"
10166 interactive mode, if you want to delete multiple records or issue additional commands. The interactive prompt appears in
10167 the following step. <PRE
10168 CLASS="programlisting"
10191 >backup dumpinfo</B
10194 list information from the Backup Database that can help you decide which records to delete. For detailed instructions, see
10196 HREF="c15383.html#HDRWQ303"
10197 >To display dump records</A
10199 CLASS="programlisting"
10200 > backup> <SPAN
10240 >backup deletedump</B
10242 > command to delete one or more dump sets.
10244 CLASS="programlisting"
10245 > backup> <SPAN
10293 CLASS="variablelist"
10305 >Is the shortest acceptable abbreviation of <SPAN
10323 >Specifies the dump ID of each initial dump to delete from the Backup Database. The records for all
10324 associated appended dumps are also deleted. Provide either this argument or the <SPAN
10330 > (and optionally, <SPAN
10348 >Specifies the beginning of a range of dates; the record for any dump created during the indicated period of
10349 time is deleted.</P
10351 >To omit all records before the time indicated with the <SPAN
10358 this argument. Otherwise provide a value in the following format</P
10360 >mm/dd/yyyy [hh:MM]</P
10362 >where the month (mm), day (dd), and year (yyyy) are required. You can omit the hour and minutes (hh:MM) to
10363 indicate the default of midnight (00:00 hours). If you provide them, use 24-hour format (for example, the value
10370 > represents 2:36 p.m.).</P
10372 >You must provide the <SPAN
10378 > argument along with this one.</P
10386 >A plus sign follows this argument in the command's syntax statement because it accepts a multiword value
10387 which does not need to be enclosed in double quotes or other delimiters, not because it accepts multiple dates.
10388 Provide only one date (and optionally, time) definition.</P
10402 >Specifies the end of a range of dates; the record of any dump created during the range is deleted from the
10403 Backup Database.</P
10405 >To delete all records created after the date you specify with the <SPAN
10412 argument, specify the value <SPAN
10418 >. To delete every dump record in the Backup
10419 Database, provide the value <SPAN
10425 > and omit the <SPAN
10431 > argument. Otherwise, provide a date value in the same format as described for the
10438 > argument. Valid values for the year (yyyy) range from <SPAN
10450 >; higher values are not valid because the
10451 latest possible date in the standard UNIX representation is in early 2038. The command interpreter automatically
10452 reduces any later date to the maximum value in 2038.</P
10454 >If you omit the time portion (hh:MM), it defaults to 59 seconds after midnight (00:00:59 hours). Similarly,
10461 > command interpreter automatically adds 59 seconds to any time value
10462 you provide. In both cases, adding 59 seconds compensates for how the Backup Database and <SPAN
10466 >backup dumpinfo</B
10468 > command represent dump creation times in hours and minutes only. For
10469 example, the Database records a creation timestamp of <SAMP
10470 CLASS="computeroutput"
10473 operation that begins between 20:55:00 and 20:55:59. Automatically adding 59 seconds to a time thus includes the
10474 records for all dumps created during that minute.</P
10476 >Provide either this argument, or the <SPAN
10482 > argument. This argument is
10483 required if the <SPAN
10489 > argument is provided.</P
10497 >A plus sign follows this argument in the command's syntax statement because it accepts a multiword value
10498 which does not need to be enclosed in double quotes or other delimiters, not because it accepts multiple dates.
10499 Provide only one date (and optionally, time) definition.</P
10515 WIDTH="100%"><TABLE
10516 SUMMARY="Footer navigation table"
10555 >Configuring the AFS Backup System</TD
10569 >Monitoring and Auditing AFS Performance</TD
git://git.openafs.org / openafs.git / blob