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-<H1>Administration Guide</H1>
-<HR><P ALIGN="center"> <A HREF="../index.htm"><IMG SRC="../books.gif" BORDER="0" ALT="[Return to Library]"></A> <A HREF="auagd002.htm#ToC"><IMG SRC="../toc.gif" BORDER="0" ALT="[Contents]"></A> <A HREF="auagd010.htm"><IMG SRC="../prev.gif" BORDER="0" ALT="[Previous Topic]"></A> <A HREF="#Bot_Of_Page"><IMG SRC="../bot.gif" BORDER="0" ALT="[Bottom of Topic]"></A> <A HREF="auagd012.htm"><IMG SRC="../next.gif" BORDER="0" ALT="[Next Topic]"></A> <A HREF="auagd026.htm#HDRINDEX"><IMG SRC="../index.gif" BORDER="0" ALT="[Index]"></A> <P>
-<HR><H1><A NAME="HDRWQ333" HREF="auagd002.htm#ToC_270">Configuring the AFS Backup System</A></H1>
-<P>The AFS Backup System helps you to create backup copies of
-data from AFS volumes and to restore data to the file system if it is lost or
-corrupted. This chapter explains how to configure the Backup
-System. For instructions on backing up and restoring data and
-displaying dump records, see <A HREF="auagd012.htm#HDRWQ382">Backing Up and Restoring AFS Data</A>.
-<HR><H2><A NAME="HDRWQ334" HREF="auagd002.htm#ToC_271">Summary of Instructions</A></H2>
-<P>This chapter explains how to perform the following tasks by
-using the indicated commands:
-<BR>
-<TABLE WIDTH="100%">
-<TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Determine tape capacity and filemark size
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>fms</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Define Tape Coordinator entry in Backup Database
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup addhost</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Remove Tape Coordinator entry from Backup Database
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup delhost</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Display Tape Coordinator entries from Backup Database
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup listhosts</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Create volume set
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup addvolset</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Add volume entry to volume set
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup addvolentry</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">List volume sets and entries
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup listvolsets</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Delete volume set from Backup Database
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup delvolset</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Delete volume entry from volume set
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup delvolentry</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Define dump level
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup adddump</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Change expiration date on existing dump level
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup setexp</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Delete dump level from dump hierarchy
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup deldump</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Display dump hierarchy
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup listdumps</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Label tape
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup labeltape</B>
-</TD></TR><TR>
-<TD ALIGN="LEFT" VALIGN="TOP" WIDTH="70%">Read label on tape
-</TD><TD ALIGN="LEFT" VALIGN="TOP" WIDTH="30%"><B>backup readlabel</B>
-</TD></TR></TABLE>
-<HR><H2><A NAME="HDRWQ350" HREF="auagd002.htm#ToC_272">Introduction to Backup System Features</A></H2>
-<A NAME="IDX6805"></A>
-<P>The AFS Backup System is highly flexible, enabling you to control most
-aspects of the backup process, including how often backups are performed,
-which volumes are backed up, and whether to dump all of the data in a volume
-or just the data that has changed since the last dump operation. You
-can also take advantage of several features that automate much of the backup
-process.
-<P>To administer and use the Backup System most efficiently, it helps to be
-familiar with its basic features, which are described in the following
-sections. For pointers to instructions for implementing the features as
-you configure the Backup System in your cell, see <A HREF="#HDRWQ356">Overview of Backup System Configuration</A>.
-<P><H3><A NAME="HDRWQ351" HREF="auagd002.htm#ToC_273">Volume Sets and Volume Entries</A></H3>
-<A NAME="IDX6806"></A>
-<A NAME="IDX6807"></A>
-<A NAME="IDX6808"></A>
-<A NAME="IDX6809"></A>
-<A NAME="IDX6810"></A>
-<P>When you back up AFS data, you specify which data to include in terms of
-complete volumes rather than individual files. More precisely, you
-define groups of volumes called <I>volume sets</I>, each of which includes
-one or more volumes that you want to back up in a single operation. You
-must include a volume in a volume set to back it up, because the command that
-backs up data (the <B>backup dump</B> command) does not accept individual
-volume names.
-<P>A volume set consists of one or more <I>volume entries</I>, each of
-which specifies which volumes to back up based on their location (file server
-machine and partition) and volume name. You can use a wildcard notation
-to include all volumes that share a location, a common character string in
-their names, or both.
-<P>For instructions on creating and removing volume sets and volume entries,
-see <A HREF="#HDRWQ364">Defining and Displaying Volume Sets and Volume Entries</A>.
-<P><H3><A NAME="Header_274" HREF="auagd002.htm#ToC_274">Dumps and Dump Sets</A></H3>
-<A NAME="IDX6811"></A>
-<A NAME="IDX6812"></A>
-<A NAME="IDX6813"></A>
-<A NAME="IDX6814"></A>
-<A NAME="IDX6815"></A>
-<A NAME="IDX6816"></A>
-<A NAME="IDX6817"></A>
-<A NAME="IDX6818"></A>
-<A NAME="IDX6819"></A>
-<A NAME="IDX6820"></A>
-<P>A <I>dump</I> is the collection of data that results from backing up a
-volume set. A <I>full dump</I> includes all of the data in every
-volume in the volume set, as it exists at the time of the dump
-operation. An <I>incremental dump</I> includes only some of the
-data from the volumes in the volume set, namely those files and directory
-structures that have changed since a specified previous dump operation was
-performed. The previous dump is referred to as the incremental
-dump's <I>parent dump</I>, and it can be either a full dump or an
-incremental dump itself.
-<P>A <I>dump set</I> is a collection of one or more dumps stored together
-on one or more tapes. The first dump in the dump set is the
-<I>initial dump</I>, and any subsequent dump added onto the end of an
-existing dump set is an <I>appended dump</I>. Appending dumps is
-always optional, but maximizes use of a tape's capacity. In
-contrast, creating only initial dumps can result in many partially filled
-tapes, because an initial dump must always start on a new tape, but does not
-necessarily extend to the end of the tape. Appended dumps do not have
-to be related to one another or to the initial dump (they do not have to be
-dumps of the same or related volume sets), but well-planned appending can
-reduce the number of times you have to change tapes during a restore
-operation. For example, it can make sense to append incremental dumps
-of a volume set together in a single dump set.
-<P>All the records for a dump set are indexed together in the Backup Database
-based on the initial dump (for more on the Backup Database, see <A HREF="#HDRWQ355">The Backup Database and Backup Server Process</A>). To delete the database record of an appended dump,
-you must delete the initial dump record, and doing so deletes the records for
-all dumps in the dump set. Similarly, you cannot recycle just one tape
-in a dump set without deleting the database records of all tapes in the dump
-set.
-<P>For instructions on creating an initial dump, see <A HREF="auagd012.htm#HDRWQ411">Backing Up Data</A>, and to learn how to append dumps, see <A HREF="auagd012.htm#HDRWQ414">Appending Dumps to an Existing Dump Set</A>.
-<P><H3><A NAME="Header_275" HREF="auagd002.htm#ToC_275">Dump Hierarchies, Dump Levels and Expiration Dates</A></H3>
-<A NAME="IDX6821"></A>
-<A NAME="IDX6822"></A>
-<A NAME="IDX6823"></A>
-<A NAME="IDX6824"></A>
-<A NAME="IDX6825"></A>
-<A NAME="IDX6826"></A>
-<P>A <I>dump hierarchy</I> is a logical structure that defines the
-relationship between full and incremental dumps; that is, it defines
-which dump serves as the parent for an incremental dump. Each
-individual component of a hierarchy is a <I>dump level</I>. When
-you create a dump by issuing the <B>backup dump</B> command, you specify a
-volume set name and a dump level name. The Backup System uses the dump
-level to determine whether the dump is full or incremental, and if
-incremental, which dump level to use as the parent.
-<P>You can associate an <I>expiration date</I> with a dump level, to
-define when a dump created at that level expires. The Backup System
-refuses to overwrite a tape until all dumps in the dump set to which the tape
-belongs have expired, so assigning expiration dates automatically determines
-how you recycle tapes. You can define an expiration date either in
-absolute terms (for example, 13 January 2000) or relative terms (for example,
-30 days from when the dump is created). You can also change the
-expiration date associated with a dump level (but not with an actual dump that
-has already been created at that level).
-<P>For instructions on creating dump hierarchies, assigning expiration dates,
-and establishing a tape recycling schedule, see <A HREF="#HDRWQ366">Defining and Displaying the Dump Hierarchy</A>.
-<A NAME="IDX6827"></A>
-<A NAME="IDX6828"></A>
-<A NAME="IDX6829"></A>
-<A NAME="IDX6830"></A>
-<A NAME="IDX6831"></A>
-<A NAME="IDX6832"></A>
-<P><H3><A NAME="HDRWQ352" HREF="auagd002.htm#ToC_276">Dump Names and Tape Names</A></H3>
-<P>When you create a dump, the Backup System creates a Backup
-Database record for it, assigning a name comprising the volume set name and
-the last element in the dump level pathname:
-<PRE> <VAR>volume_set_name</VAR><B>.</B><VAR>dump_level_name</VAR>
-</PRE>
-<P>For example, a dump of the volume set <B>user</B> at the dump level
-<B>/sunday/friday</B> is called <B>user.friday</B>. The
-Backup System also assigns a unique <I>dump ID</I> number to the dump to
-distinguish it from other dumps with the same name that possibly exist.
-<P>The Backup System assigns a similar <I>AFS tape name</I> to each tape
-that contains a dump set, reflecting the volume set and dump level of the dump
-set's initial dump, plus a numerical index of the tape's position in
-the dump set, and a unique dump ID number:
-<PRE> <VAR>volume_set_name</VAR><B>.</B><VAR>dump_level_name</VAR><B>.</B><VAR>tape_index</VAR> (<VAR>dump ID</VAR>)
-</PRE>
-<P>For example, the second tape in a dump set whose initial dump is of the
-volume set <B>uservol</B> at the dump level <B>/sunday/friday</B> has
-AFS tape name like <B>uservol.friday.2</B>
-(<B>914382400</B>).
-<P>In addition to its AFS tape name, a tape can have an optional
-<I>permanent name</I> that you assign. Unlike the AFS tape name,
-the permanent name does not have to indicate the volume set and dump level of
-the initial (or any other) dump, and so does not change depending on the
-contents of the tape. The Backup System does not require a certain
-format for permanent names, so you need to make sure that each tape's
-name is unique. If a tape has a permanent name, the Backup System uses
-it rather than the AFS tape name when referring to the tape in prompts and the
-output from most <B>backup</B> commands, but still tracks the AFS tape
-name internally.
-<P><H3><A NAME="HDRWQ353" HREF="auagd002.htm#ToC_277">Tape Labels, Dump Labels, and EOF Markers</A></H3>
-<A NAME="IDX6833"></A>
-<A NAME="IDX6834"></A>
-<A NAME="IDX6835"></A>
-<A NAME="IDX6836"></A>
-<P>Every tape used in the Backup System has a magnetic label at the beginning
-that records the tape's name, capacity, and other information. You
-can use the <B>backup labeltape</B> command to write a label, or the
-<B>backup dump</B> command creates one automatically if you use an
-unlabeled tape. The label records the following information:
-<UL>
-<P><LI>The tape's permanent name, which you can assign by using the
-<B>-pname</B> argument to the <B>backup labeltape</B> command.
-It can be any string of up to 32 characters. If you do not assign a
-permanent name, the Backup System records the value <TT><NULL></TT> when
-you use the <B>backup labeltape</B> command to assign an AFS tape name, or
-when you use the <B>backup dump</B> command to write a dump to the
-tape.
-<P><LI>The tape's AFS <I>tape name</I>, which can be one of three types
-of values:
-<UL>
-<P><LI>A name that reflects the volume set and dump level of the dump set's
-initial dump and the tape's place in the sequence of tapes for the dump
-set, as described in <A HREF="#HDRWQ352">Dump Names and Tape Names</A>. If the tape does not have a permanent name, you can
-assign the AFS tape name by using the <B>-name</B> argument to the
-<B>backup labeltape</B> command.
-<P><LI>The value <TT><NULL></TT>, which results when you assign a permanent
-name, or provide no value for the <B>backup labeltape</B> command's
-<B>-name</B> argument.
-<P><LI>No AFS tape name at all, indicating that you have never labeled the tape
-or written a dump to it.
-</UL>
-<P>If a tape does not already have an actual AFS tape name when you write a
-dump to it, the Backup System constructs and records the appropriate AFS tape
-name. If the tape does have an AFS tape name and you are writing an
-initial dump, then the name must correctly reflect the dump's volume set
-and dump level.
-<P><LI>The capacity, or <I>size</I>, of the tape, followed by a letter that
-indicates the unit of measure (<TT>k</TT> or <TT>K</TT> for kilobytes,
-<TT>m</TT> or <TT>M</TT> for megabytes, <TT>g</TT> or <TT>G</TT> for
-gigabytes, or <TT>t</TT> or <TT>T</TT> for terabytes). The
-tape's manufacturer determines the tape's capacity. For
-further discussion of how the Backup System uses the value in the capacity
-field, see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-</UL>
-<P>For information about labeling tapes, see <A HREF="#HDRWQ371">Writing and Reading Tape Labels</A>.
-<P>In addition to the tape label, the Backup System writes a <I>dump
-label</I> on the tape for every appended dump (the tape label and dump label
-are the same for the initial dump). A dump label records the following
-information:
-<UL>
-<P><LI>The name of the tape containing the dump
-<P><LI>The date and time that the dump operation began
-<P><LI>The cell to which the volumes in the dump belong
-<P><LI>The dump's size in kilobytes
-<P><LI>The dump's dump level
-<P><LI>The dump's dump ID
-</UL>
-<P>The Backup System writes a <I>filemark</I> (also called an End-of-File
-or EOF marker) between the data from each volume in a dump. The tape
-device's manufacturer determines the filemark size, which is typically
-between 2 KB and 2 MB; in general, the larger the usual capacity of the
-tapes that the device uses, the larger the filemark size. If a dump
-contains a small amount of data from each of a large number of volumes, as
-incremental dumps often do, then the filemark size can significantly affect
-how much volume data fits on the tape. To enable the Backup System to
-factor in filemark size as it writes a dump, you can record the filemark size
-in a configuration file; see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-<P><H3><A NAME="HDRWQ354" HREF="auagd002.htm#ToC_278">Tape Coordinator Machines, Port Offsets, and Backup Data Files</A></H3>
-<A NAME="IDX6837"></A>
-<A NAME="IDX6838"></A>
-<A NAME="IDX6839"></A>
-<A NAME="IDX6840"></A>
-<P>A <I>Tape Coordinator machine</I> is a machine that drives one or more
-attached tape devices used for backup operations. It must run the AFS
-client software (the Cache Manager) but reside in a physically secure location
-to prevent unauthorized access to its console. Before backup operations
-can run on a Tape Coordinator machine, each tape device on the machine must be
-registered in the Backup Database, and certain files and directories must
-exist on the machine's local disk; for instructions, see <A HREF="#HDRWQ361">To configure a Tape Coordinator machine</A>.
-<P>Each tape device on a Tape Coordinator machine listens for backup requests
-on a different UNIX port. You pick the port indirectly by assigning a
-<I>port offset number</I> to the tape device. The Backup System
-sets the device's actual port by adding the port offset to a base port
-number that it determines internally. For instructions on assigning
-port offset numbers, see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-<P>For a tape device to perform backup operations, a Backup Tape Coordinator
-(<B>butc</B>) process dedicated to the device must be running actively on
-the Tape Coordinator machine. You then direct backup requests to the
-device's Tape Coordinator by specifying its port offset number with the
-<B>-portoffset</B> argument to the <B>backup</B> command.
-<P>In addition to writing backup data to tape, you can direct it to a
-<I>backup data file</I> on the local disk of a Tape Coordinator
-machine. You can then to transfer the data to a data-archiving system,
-such as a hierarchical storage management (HSM) system, that you use in
-conjunction with AFS and the Backup System. A backup data file has a
-port offset like a tape device. For instructions on configuring backup
-data files, see <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A>.
-<P><H3><A NAME="HDRWQ355" HREF="auagd002.htm#ToC_279">The Backup Database and Backup Server Process</A></H3>
-<A NAME="IDX6841"></A>
-<A NAME="IDX6842"></A>
-<P>The <I>Backup Database</I> is a replicated administrative database
-maintained by the <I>Backup Server</I> process on the cell's database
-server machines. Like the other AFS database server processes, the
-Backup Server uses the Ubik utility to keep the various copies of the database
-synchronized (for a discussion of Ubik, see <A HREF="auagd007.htm#HDRWQ67">Replicating the AFS Administrative Databases</A>).
-<P>The Backup Database records the following information:
-<UL>
-<P><LI>The Tape Coordinator machine's hostname and the port offset number
-for each tape device used for backup operations
-<P><LI>The dump hierarchy, which consists of its component dump levels and their
-associated expiration dates
-<P><LI>The volume sets and their component volume entries
-<P><LI>A record for each dump, which includes the name of each tape it appears
-on, a list of the volumes from which data is included, the dump level, the
-expiration date, and the dump ID of the initial dump with which the dump is
-associated
-<P><LI>A record for each tape that houses dumped data
-</UL>
-<P><H3><A NAME="Header_280" HREF="auagd002.htm#ToC_280">Interfaces to the Backup System</A></H3>
-<P>The <B>backup</B> suite of commands is the administrative interface
-to the Backup System. You can issue the commands in a command shell (or
-invoke them in a shell script) on any AFS client or server machine from which
-you can access the <B>backup</B> binary. In the conventional
-configuration, the binary resides on the local disk.
-<P>The <B>backup</B> command suite provides an <I>interactive
-mode</I>, in which you can issue multiple commands over a persistent
-connection to the Backup Server and the Volume Location (VL) Server.
-Interactive mode has several convenient features, including the
-following:
-<UL>
-<P><LI>You need to type only the operation code, omitting the initial
-<B>backup</B> string.
-<P><LI>If you assume another AFS identity or specify a foreign cell as you enter
-interactive mode, it applies to all subsequent commands.
-<P><LI>You do not need to enclose shell metacharacters in double quotes.
-<P><LI>You can track current and pending operations with the <B>(backup)
-jobs</B> command, which is available only in this mode.
-<P><LI>You can cancel current and pending operations with the <B>(backup)
-kill</B> command, which is available only in this mode.
-</UL>
-<P>Before issuing a command that requires reading or writing a tape (or backup
-data file), you must also open a connection to the Tape Coordinator machine
-that is attached to the relevant tape device (or that has the backup data file
-on its local disk), and issue the <B>butc</B> command to initialize the
-Tape Coordinator process. The process must continue to run and the
-connection remain open as long as you need to use the tape device or file for
-backup operations.
-<P>For further discussion and instructions, see <A HREF="auagd012.htm#HDRWQ401">Using the Backup System's Interfaces</A>.
-<HR><H2><A NAME="HDRWQ356" HREF="auagd002.htm#ToC_281">Overview of Backup System Configuration</A></H2>
-<A NAME="IDX6843"></A>
-<P>Before you can use the Backup System to back up and restore data, you must
-configure several of its basic components. The indicated sections of
-this chapter explain how to perform the following configuration tasks:
-<UL>
-<P><LI>Determining a tape's capacity and a tape device's filemark size,
-and recording them in the <B>/usr/afs/backup/tapeconfig</B> file (see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>)
-<P><LI>Determining how to grant administrative privilege to backup operators (see
-<A HREF="#HDRWQ359">Granting Administrative Privilege to Backup Operators</A>)
-<P><LI>Configuring Tape Coordinator machines, tape devices, and backup data files
-(see <A HREF="#HDRWQ360">Configuring Tape Coordinator Machines and Tape Devices</A>)
-<P><LI>Defining volume sets and volume entries (see <A HREF="#HDRWQ364">Defining and Displaying Volume Sets and Volume Entries</A>)
-<P><LI>Defining dump levels to create a dump hierarchy (see <A HREF="#HDRWQ366">Defining and Displaying the Dump Hierarchy</A>)
-<P><LI>Labeling tapes (see <A HREF="#HDRWQ371">Writing and Reading Tape Labels</A>)
-<P><LI>Creating a device configuration file to automate the backup process (see <A HREF="#HDRWQ374">Automating and Increasing the Efficiency of the Backup Process</A>)
-</UL>
-<P>If you have already configured all of the components required for
-performing a backup dump or restore operation, you can proceed to the
-instructions in <A HREF="auagd012.htm#HDRWQ411">Backing Up Data</A> and <A HREF="auagd012.htm#HDRWQ421">Restoring and Recovering Data</A>.
-<HR><H2><A NAME="HDRWQ357" HREF="auagd002.htm#ToC_282">Configuring the tapeconfig File</A></H2>
-<A NAME="IDX6844"></A>
-<A NAME="IDX6845"></A>
-<A NAME="IDX6846"></A>
-<A NAME="IDX6847"></A>
-<A NAME="IDX6848"></A>
-<P>Several factors interact to determine how much data the Tape Coordinator
-can fit on a tape:
-<UL>
-<P><LI>The tape's capacity (size), as set by the tape manufacturer.
-<P><LI>The tape device's filemark size, as set by the tape device's
-manufacturer. Recall from <A HREF="#HDRWQ353">Tape Labels, Dump Labels, and EOF Markers</A> that the Tape Coordinator writes a filemark between the data
-from each volume in a dump. If a dump contains a small amount of data
-from each of a large number of volumes, as incremental dumps often do, then
-the filemark size can significantly affect how much volume data fits on the
-tape.
-<P><LI>Whether or not you use the tape device's compression mode.
-</UL>
-<P>(The amount of data that can fit in a backup data file is determined by
-amount of space available on the partition, and the operating system's
-maximum file size. The Tape Coordinator does not write filemarks when
-writing to a backup data file. For further information about
-configuring a Tape Coordinator to write to a backup data file, see <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A>.)
-<P>As the Tape Coordinator (<B>butc</B>) process initializes, it reads the
-<B>/usr/afs/backup/tapeconfig</B> file on its local disk to learn the tape
-capacity and filemark size (for a tape device) or the file size (for a backup
-data file) to use for dump operations. When you begin a dump operation,
-the Tape Coordinator also reads the tape or backup data file's label to
-see if you have recorded a different tape capacity or file size. If you
-have, the value on the label overrides the default value from the
-<B>tapeconfig</B> file.
-<P>As the Tape Coordinator writes data to a tape during a dump operation, it
-uses the capacity and filemark information to track how much tape it has used
-and how much remains before the physical end-of-tape (EOT). Shortly
-before reaching EOT, the Tape Coordinator stops writing and requests a new
-tape. Similarly, it uses a backup data file's size to know when it
-is about to exhaust the space in the file. If the Tape Coordinator
-reaches the EOT unexpectedly, it recovers by obtaining a new tape and writing
-to it the entire contents of the volume it was writing when it reached
-EOT. The interrupted volume remains on the first tape, but is never
-used.
-<P>Many tape devices use tapes that can accommodate multiple gigabytes, or
-even multiple terabytes, of backup data, especially if you use the
-device's compression mode. When writing to such devices and tapes,
-allowing the Tape Coordinator to hit the EOT unexpectedly is generally
-recommended. The devices write data so quickly that it usually does not
-take much extra time to rewrite the interrupted volume on the new tape.
-Similarly, they compress data so well that the data abandoned on the first
-tape from the interrupted volume does not constitute a waste of much
-tape.
-<P>When writing to tapes that accommodate a smaller amount of data (say, less
-than two GB), it is better to avoid having the Tape Coordinator hit EOT
-unexpectedly. AFS supports volumes up to 2 GB in size, so an
-interrupted volume can in fact take up most of the tape. For such
-tapes, recording accurate values for tape capacity and filemark size, if
-possible, helps to maximize both use of tape and the efficiency of dump
-operations. The following discussion of the fields in the
-<B>tapeconfig</B> file explains how to determine the appropriate
-values.
-<P>Use a text editor to create an entry in a Tape Coordinator's
-<B>tapeconfig</B> file for each tape device or backup data file that it
-uses. Each device or file's entry is on its own line and has the
-following format:
-<PRE> [<VAR>capacity</VAR> <VAR>filemark_size</VAR>] <VAR>device_name</VAR> <VAR>port_offset</VAR>
-</PRE>
-<P>where
-<DL>
-<P><DT><B><VAR>capacity</VAR>
-</B><DD>Specifies the capacity of the tapes used with a tape device, or the amount
-of data to write into a backup data file. Specify an integer value
-followed by a letter that indicates units, with no intervening space.
-The letter <B>k</B> or <B>K</B> indicates kilobytes, <B>m</B> or
-<B>M</B> indicates megabytes, <B>g</B> or <B>G</B> indicates
-gigabytes, and <B>t</B> or <B>T</B> indicates terabytes. If the
-units letter is omitted, the default is kilobytes.
-<P>To determine the capacity of a tape under two GB in size that you are going
-to use in regular (noncompression) mode, you can either use the value that the
-tape's manufacturer specifies on the tape's packaging or use the
-<B>fms</B> command to calculate the capacity, as described later in this
-section. To avoid having the Tape Coordinator reach the EOT
-unexpectedly, it is best to record in the <B>tapeconfig</B> file or on the
-label a capacity that is about 10% smaller than the actual capacity of the
-tape. To calculate the appropriate value for a small tape used in
-compression mode, one method is to multiply the tape capacity (as recorded by
-the manufacturer) by the device's compression ratio.
-<P>For tapes that hold multiple gigabytes or terabytes of data, or if using a
-tape drive's compression mode, the recommended configuration is to record
-a value quite a bit (for instance, two times) larger than the maximum amount
-you believe can fit on the tape. It is not generally worthwhile to run
-the <B>fms</B> command on large tapes, even in noncompression mode.
-The command definitely does not yield accurate results in compression
-mode. The Tape Coordinator is likely to reach the EOT unexpectedly, but
-compression mode fits so much data on the tape that the data abandoned from an
-interrupted volume does not represent much of the tape's capacity.
-<P>For a backup data file, record a value slightly smaller than the amount of
-space available on the partition, and definitely smaller than the operating
-system's maximum file size. It is also best to limit the ability
-of other processes to write to the partition, to prevent them from using up
-the space in the partition.
-<P>If this field is empty, the Tape Coordinator uses the maximum acceptable
-value (2048 GB or 2 TB). Either leave both this field and the
-<VAR>filemark_size</VAR> field empty, or provide a value in both of them.
-<P><DT><B><VAR>filemark_size</VAR>
-</B><DD>Specifies the tape device's filemark size, which usually falls
-between 2 KB and 2 MB. Use the same notation as for the
-<VAR>capacity</VAR> field, but note that if you omit the units letter, the
-default unit is bytes rather than kilobytes.
-<P>For a tape device in regular (noncompression) mode, you can use the
-<B>fms</B> command to determine filemark size, or use the value reported
-by the device's manufacturer. To help the Tape Coordinator avoid
-reaching EOT unexpectedly, increase the value by about 10% when recording it
-in the <B>tapeconfig</B> file.
-<P>The recommended value for a tape device in compression mode is <B>0</B>
-(zero). The <B>fms</B> command does not yield accurate results in
-compression mode, so you cannot use it to determine the filemark size.
-<P>The recommended value for a backup data file is also <B>0</B>
-(zero). The Tape Coordinator does not use filemarks when writing to a
-file, but a value must appear in this field nevertheless if there is also a
-value in the <VAR>capacity</VAR> field.
-<P>If this field is empty, the Tape Coordinator uses the value <B>0</B>
-(zero). Either leave both this field and the <VAR>capacity</VAR> field
-empty, or provide a value in both of them.
-<P><DT><B><VAR>device_name</VAR>
-</B><DD>Specifies the complete pathname of the tape device or backup data
-file. The format of tape device names depends on the operating system,
-but on UNIX systems, device names generally begin with the string
-<B>/dev/</B>. For a backup data file, this field defines the
-complete pathname, but for suggestions on how to name a backup data file, see <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A>.
-<P><DT><B><VAR>port_offset</VAR>
-</B><DD>Specifies the port offset number for a specific tape device or backup data
-file. Each tape device listens for backup requests on a different UNIX
-port. You pick the port indirectly by recording a value in this
-field. The Backup System sets the device's actual port by adding
-the port offset to a base port number that it determines internally.
-<P>Legal values are the integers <B>0</B> through <B>58510</B> (the
-Backup System can track a maximum of 58,511 port offset numbers). Each
-value must be unique among the cell's Tape Coordinators, but you do not
-have to assign port offset numbers sequentially, and you can associate any
-number of them with a single machine or even tape device. For example,
-if you plan to use a device in both compression and noncompression mode,
-assign it two different port offsets with appropriate tape capacity and
-filemark values for the different modes.
-<P>Assign port offset <B>0</B> (zero) to the Tape Coordinator for the tape
-device or backup data file that you use most often for backup operations;
-doing so enables you to omit the <B>-portoffset</B> argument from the
-largest possible number of <B>backup</B> commands.
-</DL>
-<P>The following example <B>tapeconfig</B> file includes entries for two
-tape devices, <B>/dev/rmt0h</B> and <B>/dev/rmt1h</B>. Each one
-uses tapes with a capacity of 2 GB and has a filemark size of 1 MB.
-Their port offset numbers are <TT>0</TT> and <TT>1</TT>.
-<PRE> 2g 1m /dev/rmt0h 0
- 2G 1M /dev/rmt1h 1
-</PRE>
-<P>The <B>fms</B> command reports the capacity of the tape you have
-inserted and the tape device's filemark size, both on the standard output
-stream (stdout) and in its <B>fms.log</B> file, which it writes in
-the current working directory. The command interpreter must write data
-to the entire tape, so running the command can take from several hours to more
-than a day, depending on the size of the tape.
-<P><H3><A NAME="HDRWQ358" HREF="auagd002.htm#ToC_283">To run the fms command on a noncompressing tape device</A></H3>
-<A NAME="IDX6849"></A>
-<A NAME="IDX6850"></A>
-<A NAME="IDX6851"></A>
-<A NAME="IDX6852"></A>
-<A NAME="IDX6853"></A>
-<OL TYPE=1>
-<P><LI>If an <B>fms.log</B> file does not already exist in the current
-directory, verify that you can insert and write to files in the current
-directory. If the log file already exists, you must be able to write to
-the file.
-<P><LI>Insert a tape into the drive. Running the command completely
-overwrites the tape, so use a blank tape or one that you want to
-recycle.
-<P><LI>Issue the <B>fms</B> command.
-<PRE> % <B>fms</B> <<VAR>tape special file</VAR>>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>fms
-</B><DD>Must be typed in full.
-<P><DT><B><VAR>tape special file</VAR>
-</B><DD>Specifies the tape device's UNIX device name, such as
-<B>/dev/rmt0h</B>.
-</DL>
-</OL>
-<P>The following example output reports that the tape in the device with
-device name <B>/dev/rmt0h</B> has a capacity of 2136604672 bytes (about 2
-GB), and that the device's filemark size is 1910205 bytes (close to 2
-MB).
-<PRE> % <B>fms /dev/rmt0h</B>
- wrote block: 130408
- Finished data capacity test - rewinding
- wrote 1109 blocks, 1109 file marks
- Finished file mark test
- Tape capacity is 2136604672 bytes
- File marks are 1910205 bytes
-</PRE>
-<HR><H2><A NAME="HDRWQ359" HREF="auagd002.htm#ToC_284">Granting Administrative Privilege to Backup Operators</A></H2>
-<P>Each person who issues the <B>backup</B> and
-<B>butc</B> commands in your cell must be listed in the
-<B>/usr/afs/etc/UserList</B> file on every database server machine that
-stores the Backup Database and Volume Location Database (VLDB), and every
-machine that houses a volume included in a volume set. By convention,
-the <B>UserList</B> file is the same on every server machine in the
-cell; the instructions in this document assume that your cell is
-configured in this way. To edit the <B>UserList</B> file, use the
-<B>bos adduser</B> and <B>bos removeuser</B> commands as described in <A HREF="auagd021.htm#HDRWQ814">Administering the UserList File</A>.
-<P>In addition to being listed in the <B>UserList</B> file, backup
-operators who issue the <B>butc</B> command must be able to write to the
-files stored in each Tape Coordinator machine's local
-<B>/usr/afs/backup</B> directory, which are protected by UNIX mode
-bits. Before configuring your cell's first Tape Coordinator
-machine, decide which local user and group to designate as the owner of the
-directory and the files in it. Among the possible ownership options are
-the following:
-<UL>
-<P><LI>The local superuser <B>root</B>. With this option, the issuer
-of the <B>butc</B> command must log onto the local file system as the
-local superuser <B>root</B>. If the Tape Coordinator is also a
-server machine, the <B>-localauth</B> flag is used on the <B>butc</B>
-command to construct a server ticket from the local
-<B>/usr/afs/etc/KeyFile</B> file. On non-server machine, the issuer
-must issue the <B>klog</B> command to authenticate as an AFS administrator
-while logged in as <B>root</B>.
-<P><LI>A single AFS administrator. Logging in and authenticating are a
-single step if an AFS-modified login utility is used. The administrator
-is the only user who can start the Tape Coordinator.
-<P><LI>An administrative account for which several operators know the
-password. This allows them all to start the Tape Coordinator.
-</UL>
-<P>Another option is to define a group in the local group file
-(<B>/etc/group</B> or equivalent) to which all backup operators
-belong. Then turn on the <B>w</B> mode bit (<B>write</B>
-permission) in the group mode bits rather than the user mode bits of the
-<B>/usr/afs/backup</B> directory and files in it. An advantage over
-the methods listed previously is that each operator can retain an individual
-administrative account for finer granularity in auditing.
-<P>For instructions on implementing your choice of protection methods, see <A HREF="#HDRWQ360">Configuring Tape Coordinator Machines and Tape Devices</A>.
-<HR><H2><A NAME="HDRWQ360" HREF="auagd002.htm#ToC_285">Configuring Tape Coordinator Machines and Tape Devices</A></H2>
-<A NAME="IDX6854"></A>
-<A NAME="IDX6855"></A>
-<A NAME="IDX6856"></A>
-<A NAME="IDX6857"></A>
-<P>This section explains how to configure a machine as a Tape Coordinator
-machine, and how to configure or remove the Tape Coordinator associated with a
-single tape device or backup data file.
-<TABLE><TR><TD ALIGN="LEFT" VALIGN="TOP"><B>Note:</B></TD><TD ALIGN="LEFT" VALIGN="TOP">When configuring a tape device attached to an AIX system, you must set the
-device's tape block size to <B> 0</B> (zero) to indicate variable
-block size. If you do not, it is possible that devices attached to
-machines of other system types cannot read the tapes made on the AIX
-system. Use the AIX <B>smit</B> program to verify or change the
-value of the tape block size for a tape device, as instructed in Sep <A HREF="#LIWQ362">3</A>.
-</TD></TR></TABLE>
-<P><H3><A NAME="HDRWQ361" HREF="auagd002.htm#ToC_286">To configure a Tape Coordinator machine</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Become the local superuser <B>root</B> on the machine, if you are not
-already, by issuing the <B>su</B> command.
-<PRE> % <B>su root</B>
- Password: <VAR>root_password</VAR>
-</PRE>
-<P><LI><A NAME="LIWQ362"></A>Install one or more tape devices on the Tape Coordinator
-machine according to the manufacturer's instructions. The Backup
-System can track a maximum of 58,511 tape devices or backup data files per
-cell.
-<P>If the Tape Coordinator machine is an AIX system, issue the following
-command to change the tape device's tape block size to <B>0</B>
-(zero), which indicates variable block size. Repeat for each tape
-device.
-<PRE> # <B>chdev -l '</B><VAR>device_name</VAR><B>' -a block_size='0'</B>
-</PRE>
-<P>where <VAR>device_name</VAR> is the tape device's device name (for
-example, <B>/dev/rmt0h</B>).
-<P><LI>Verify that the binary files for the <B>backup</B>, <B>butc</B>,
-and <B>fms</B> commands are available on the local disk. If the
-machine is an AFS client, the conventional location is the
-<B>/usr/afsws/etc</B> directory.
-<PRE> # <B>ls /usr/afsws/etc</B>
-</PRE>
-<P><LI>Create the <B>/usr/afs</B> directory. (If the Tape Coordinator
-machine is also configured as a file server machine, this directory already
-exists.) Then create the <B>/usr/afs/backup</B> directory.
-<PRE> # <B>mkdir /usr/afs</B>
- # <B>mkdir /usr/afs/backup</B>
-</PRE>
-<P><LI>Use a text editor to create the <B>/usr/afs/backup/tapeconfig</B>
-file. Include a single line for each tape device or backup data file,
-specifying the following information in the indicated order. For syntax
-details and suggestions on the values to use in each field, see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-<UL>
-<P><LI>The capacity of tapes to be used in the device, or the size of the backup
-data file
-<P><LI>The device's filemark size
-<P><LI>The device's device name, starting with the string <B>/dev/</B>
-<P><LI>The device's port offset number
-</UL>
-<A NAME="IDX6858"></A>
-<A NAME="IDX6859"></A>
-<A NAME="IDX6860"></A>
-<A NAME="IDX6861"></A>
-<P><LI>Decide which user and group are to own the <B>/usr/afs/backup</B>
-directory and <B>/usr/afs/backup/tapeconfig</B> file, based on the
-suggestions in <A HREF="#HDRWQ359">Granting Administrative Privilege to Backup Operators</A>. Correct the UNIX mode bits on the directory and
-file, if necessary.
-<PRE> # <B>chown</B> <VAR>admin_owner</VAR> <B>/usr/afs/backup</B>
- # <B>chown</B> <VAR>admin_owner</VAR> <B>/usr/afs/backup/tapeconfig</B>
- # <B>chgrp</B> <VAR>admin_group</VAR> <B>/usr/afs/backup</B>
- # <B>chgrp</B> <VAR>admin_group</VAR> <B>/usr/afs/backup/tapeconfig</B>
- # <B>chmod 774 /usr/afs/backup</B>
- # <B>chmod 664 /usr/afs/backup/tapeconfig</B>
-</PRE>
-<A NAME="IDX6862"></A>
-<A NAME="IDX6863"></A>
-<A NAME="IDX6864"></A>
-<A NAME="IDX6865"></A>
-<P><LI><A NAME="LICONFTC-ADDHOST"></A>Issue the <B>backup addhost</B> command to create
-a Tape Coordinator entry in the Backup Database. Repeat the command for
-each Tape Coordinator.
-<PRE> # <B>backup addhost</B> <<VAR>tape machine name</VAR>> [<<VAR>TC port offset</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>addh
-</B><DD>Is the shortest acceptable abbreviation of <B>addhost</B>.
-<P><DT><B><VAR>tape machine name</VAR>
-</B><DD>Specifies the Tape Coordinator machine's fully qualified
-hostname.
-<P><DT><B><VAR>TC port offset</VAR>
-</B><DD>Specifies the tape device's port offset number. Provide the
-same value as you specified for the device in the <B>tapeconfig</B>
-file. You must provide this argument unless the default value of 0
-(zero) is appropriate.
-</DL>
-</OL>
-<P><H3><A NAME="Header_287" HREF="auagd002.htm#ToC_287">To configure an additional Tape Coordinator on an existing Tape Coordinator machine</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Become the local superuser <B>root</B> on the machine, if you are not
-already, by issuing the <B>su</B> command.
-<PRE> % <B>su root</B>
- Password: <VAR>root_password</VAR>
-</PRE>
-<P><LI>Install the tape device on the Tape Coordinator machine according to the
-manufacturer's instructions.
-<P>If the Tape Coordinator machine is an AIX system, issue the following
-command to change the tape device's tape block size to <B>0</B>
-(zero), which indicates variable block size.
-<PRE> # <B>chdev -l '</B><VAR>device_name</VAR><B>' -a block_size='0'</B>
-</PRE>
-<P><LI>Choose the port offset number to assign to the tape device. If
-necessary, use the <B>backup listhosts</B> command to display the port
-offset numbers that are already used; for a discussion of the output, see
-<A HREF="#HDRWQ363">To display the list of configured Tape Coordinators</A>.
-<PRE> # <B>backup listhosts</B>
-</PRE>
-<P>where <B>listh</B> is the shortest acceptable abbreviation of
-<B>listhosts</B>.
-<P><LI>Use a text editor to add one or more entries for the device to the
-<B>/usr/afs/backup/tapeconfig</B> file. Specify the following
-information in the indicated order. For syntax details and suggestions
-on the values to use in each field, see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-<UL>
-<P><LI>The capacity of tapes to be used in the device, or the size of the backup
-data file
-<P><LI>The device's filemark size
-<P><LI>The device's device name, starting with the string <B>/dev/</B>
-<P><LI>The device's port offset number
-</UL>
-<P><LI>Issue the <B>backup addhost</B> command to create an entry in the
-Backup Database for the Tape Coordinator. For complete syntax, see Step
-<A HREF="#LICONFTC-ADDHOST">8</A> in <A HREF="#HDRWQ361">To configure a Tape Coordinator machine</A>.
-<PRE> # <B>backup addhost</B> <<VAR>tape machine name</VAR>> [<<VAR>TC port offset</VAR>>]
-</PRE>
-</OL>
-<A NAME="IDX6866"></A>
-<A NAME="IDX6867"></A>
-<A NAME="IDX6868"></A>
-<A NAME="IDX6869"></A>
-<P><H3><A NAME="Header_288" HREF="auagd002.htm#ToC_288">To unconfigure a Tape Coordinator</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Using a text editor, remove each of the Tape Coordinator's entries
-from the <B>/usr/afs/backup/tapeconfig</B> file.
-<P><LI>Issue the <B>backup delhost</B> command to delete the Tape
-Coordinator's Backup Database entry.
-<PRE> % <B>backup delhost</B> <<VAR>tape machine name</VAR>> [<<VAR>TC port offset</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>delh
-</B><DD>Is the shortest acceptable abbreviation of <B>delhost</B>.
-<P><DT><B><VAR>tape machine name</VAR>
-</B><DD>Is the complete Internet host name of the Tape Coordinator machine.
-<P><DT><B><VAR>TC port offset</VAR>
-</B><DD>Is the same port offset number removed from the <B>tapeconfig</B>
-file. You must provide this argument unless the default value of
-<B>0</B> (zero) is appropriate.
-</DL>
-</OL>
-<A NAME="IDX6870"></A>
-<A NAME="IDX6871"></A>
-<A NAME="IDX6872"></A>
-<A NAME="IDX6873"></A>
-<P><H3><A NAME="HDRWQ363" HREF="auagd002.htm#ToC_289">To display the list of configured Tape Coordinators</A></H3>
-<OL TYPE=1>
-<P><LI>Issue the <B>backup listhosts</B> command to list the Tape
-Coordinators and port offset numbers currently configured in the Backup
-Database.
-<PRE> % <B>backup listhosts</B>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>listh
-</B><DD>Is the shortest acceptable abbreviation of <B>listhosts</B>.
-</DL>
-</OL>
-<P>The output lists each Tape Coordinator machine and the port offset numbers
-currently allocated to it in the Backup Database. The appearance of a
-port offset number does not imply that the associated Tape Coordinator is
-actually running. Machine names appear in the format in which they were
-specified with the <B>backup addhost</B> command.
-<P>The following example output lists the Tape Coordinators currently defined
-in the Backup Database of the ABC Corporation cell:
-<PRE> % <B>backup listhosts</B>
- Tape hosts:
- Host backup1.abc.com, port offset 0
- Host backup1.abc.com, port offset 2
- Host backup2.abc.com, port offset 1
- Host backup2.abc.com, port offset 3
-</PRE>
-<HR><H2><A NAME="HDRWQ364" HREF="auagd002.htm#ToC_290">Defining and Displaying Volume Sets and Volume Entries</A></H2>
-<P>The Backup System handles data at the level of volumes
-rather than individual files. You must define groups of volumes called
-<I>volume sets</I> before performing backup operations, by using the
-<B>backup addvolset</B> command. A volume set name can be up to 31
-characters long and can include any character other than the period
-(<B>.</B>), but avoid using metacharacters that have special
-meanings to the shell.
-<P>After creating a volume set, use the <B>backup addvolentry</B> command
-to place one or more <I>volume entries</I> in it. They define the
-volumes that belong to it in terms of their location (file server machine and
-partition) and name. Use the command's required <B>-server</B>
-argument to designate the file server machine that houses the volumes of
-interest and its required <B>-partition</B> argument to designate the
-partition. Two types of values are acceptable:
-<UL>
-<P><LI>The fully qualified hostname of one machine or full name of one partition
-(such as <B>/vicepm</B>)
-<P><LI>The regular expression <B>.*</B> (period and asterisk), which
-matches every machine name or partition name in the VLDB
-</UL>
-<P>For the volume name (the required <B>-volume</B> argument), specify a
-combination of alphanumeric characters and one or more metacharacters to
-specify part or all of the volume name with a wildcard. You can use any
-of the following metacharacters in the volume name field:
-<A NAME="IDX6874"></A>
-<A NAME="IDX6875"></A>
-<DL>
-<P><DT><B>.
-</B><DD>The period matches any single character.
-<P><DT><B>*
-</B><DD>The asterisk matches zero or more instances of the preceding
-character. Combine it with any other alphanumeric character or
-metacharacter.
-<P><DT><B>[ ]
-</B><DD>Square brackets around a list of characters match a single instance of any
-of the characters, but no other characters; for example, <B>[abc]</B>
-matches a single <B>a</B> or <B>b</B> or <B>c</B>, but not
-<B>d</B> or <B>A</B>. You can combine this expression with the
-asterisk.
-<P><DT><B>^
-</B><DD>The caret, when used as the first character in a square-bracketed set,
-designates a match with any single character other than the characters that
-follow it; for example, <B>[^a]</B> matches any single character
-except lowercase <B>a</B>. You can combine this expression with the
-asterisk.
-<P><DT><B>\
-</B><DD>A backslash preceding any of the metacharacters in this list makes it
-match its literal value only. For example, the expression
-<B>\.</B> (backslash and period) matches a single period,
-<B>\*</B> matches a single asterisk, and <B>\\</B> matches a single
-backslash. You can combine such expressions with the asterisk (for
-example, <B>\.*</B> matches any number of periods).
-</DL>
-<P>Perhaps the most common regular expression is the period followed by an
-asterisk (<B>.*</B>). This expression matches any string of
-any length, because the period matches any character and the asterisk means
-any number of that character. As mentioned, it is the only acceptable
-regular expression in the file server and partition fields of a volume
-entry. In the volume name field, it can stand alone (in which case it
-matches every volume listed in the VLDB), or can combine with alphanumeric
-characters. For example, the string
-<B>user.*\.backup</B> matches any volume name that begins
-with the string <B>user</B> and ends with
-<B>.backup</B>.
-<P>Issuing the <B>backup addvolentry</B> command in interactive mode is
-simplest. If you issue it at the shell prompt, you must surround any
-string that includes a regular expression with double quotes (<B>" "</B>)
-so that the shell passes them uninterpreted to the <B>backup</B> command
-interpreter rather than resolving them.
-<P>To define various combinations of volumes, provide the following types of
-values for the <B>backup addvolentry</B> command's three
-arguments. The list uses the notation appropriate for interactive
-mode; if you issue the command at the shell prompt instead, place double
-quotes around any string that includes a regular expression. To create
-a volume entry that includes:
-<UL>
-<P><LI>All volumes listed in the VLDB, use the regular expression
-<B>.*</B> for all three arguments (<B>-server .*
--partition .* -volume .*</B>)
-<P><LI>Every volume on a specific file server machine, specify its fully
-qualified hostname as the <B>-server</B> argument and use the regular
-expression <B>.*</B> for the <B>-partition</B> and
--<B>volume</B> arguments (for example: <B>-server
-fs1.abc.com -partition .* -volume .*</B>)
-<P><LI>All volumes that reside on a partition with the same name on various file
-server machines, specify the complete partition name as the
-<B>-partition</B> argument and use the regular expression
-<B>.*</B> for the <B>-server</B> and <B>-volume</B>
-arguments (for example: <B>-server .* -partition /vicepd
--volume .*</B>)
-<P><LI>Every volume with a common string in its name, use the regular expression
-<B>.*</B> for the <B>-server</B> and <B>-partition</B>
-arguments, and provide a combination of alphanumeric characters and
-metacharacters as the <B>-volume</B> argument (for example:
-<B>-server .* -partition .* -volume
-.*\.backup</B> includes all volumes whose names end in the
-string <B>.backup</B>).
-<P><LI>All volumes on one partition, specify the machine's fully qualified
-hostname as the <B>-server</B> argument and the full partition name as the
-<B>-partition</B> argument, and use the regular expression
-<B>.*</B> for the <B>-volume</B> argument (for example:
-<B>-server fs2.abc.com -partition /vicepb -volume
-.*</B>).
-<P><LI>A single volume, specify its complete name as the <B>-volume</B>
-argument. To bypass the potentially time-consuming search through the
-VLDB for matching entries, you can specify an actual machine and partition
-name for the <B>-server</B> and <B>-partition</B> arguments
-respectively. However, if it is possible that you need to move the
-volume in future, it is best to use the regular expression
-<B>.*</B> for the machine and partition name.
-</UL>
-<P>As you create volume sets, define groups of volumes you want to dump to the
-same tape at the same time (for example, weekly or daily) and in the same
-manner (fully or incrementally). In general, a volume set that includes
-volumes with similar contents (as indicated by similar names) is more useful
-than one that includes volumes that share a common location, especially if you
-often move volumes for load-balancing or space reasons. Most often,
-then, it is appropriate to use the regular expression <B>.*</B>
-(period followed by a backslash) for the <B>-server</B> and
-<B>-partition</B> arguments to the <B>backup addvolentry</B>
-command.
-<P>It is generally more efficient to include a limited number of volumes in a
-volume entry. Dumps of a volume set that includes a large number of
-volume can take a long time to complete, increasing the possibility that the
-operation fails due to a service interruption or outage.
-<P>To remove a volume entry from a volume set, use the <B>backup
-delvolentry</B> command. To remove a volume set and all of its
-component volume entries from the Backup Database, use the <B>backup
-delvolset</B> command. To display the volume entries in a volume set,
-use the <B>backup listvolsets</B> command.
-<P>By default, a Backup Database record is created for the new volume
-set. Sometimes it is convenient to create volume sets without recording
-them permanently in the Backup Database, for example when using the
-<B>backup volsetrestore</B> command to restore a group of volumes that
-were not necessarily backed up together (for further discussion, see <A HREF="auagd012.htm#HDRWQ427">Using the backup volsetrestore Command</A>). To create a <I>temporary</I> volume set,
-include the <B>-temporary</B> flag to the <B>backup addvolset</B>
-command. A temporary volume set exists only during the lifetime of the
-current interactive session, so the flag is effective only when used during an
-interactive session (opened by issuing the <B>backup (interactive)</B>
-command). You can use the <B>backup delvolset</B> command to delete
-a temporary volume set before the interactive session ends, if you wish, but
-as noted it is automatically deleted when you end the session. One
-advantage of temporary volume sets is that the <B>backup addvolset</B>
-command, and any <B>backup addvolentry</B> commands subsequently used to
-add volume entries to it, complete more quickly than for regular volume sets,
-because you are not creating any Backup Database records.
-<A NAME="IDX6876"></A>
-<A NAME="IDX6877"></A>
-<A NAME="IDX6878"></A>
-<A NAME="IDX6879"></A>
-<P><H3><A NAME="Header_291" HREF="auagd002.htm#ToC_291">To create a volume set</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI><B>(Optional)</B> Issue the <B>backup</B> command to enter
-interactive mode. If you are going to define volume entries right away
-with the <B>backup addvolentry</B> command, this eliminates the need to
-surround metacharacter expressions with double quotes. You must enter
-interactive mode if creating a temporary volume set.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) addvolset</B> command to create the volume
-set. You must then issue the <B>(backup) addvolentry</B> command to
-define volume entries in it.
-<PRE> backup> <B>addvolset</B> <<VAR>volume set name</VAR>> [<B>-temporary</B>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>addvols
-</B><DD>Is the shortest acceptable abbreviation of <B>addvolset</B>.
-<P><DT><B><VAR>volume set name</VAR>
-</B><DD>Names the volume set. The name can include no more than 31
-characters, cannot include periods, and must be unique within the Backup
-Database. (A temporary volume set can have the same name as an existing
-permanent volume set, but this is not recommended because of the confusion it
-can cause.)
-<P><DT><B>-temporary
-</B><DD>Creates a temporary volume set, which exists only during the current
-interactive session.
-</DL>
-</OL>
-<A NAME="IDX6880"></A>
-<A NAME="IDX6881"></A>
-<A NAME="IDX6882"></A>
-<A NAME="IDX6883"></A>
-<P><H3><A NAME="Header_292" HREF="auagd002.htm#ToC_292">To add a volume entry to a volume set</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI><B>(Optional)</B> Issue the <B>backup</B> command to enter
-interactive mode if you have not already. This makes it simpler to use
-metacharacter expressions, because you do not need to surround them with
-double quotes. If you are adding entries to a temporary volume set, you
-must already have entered interactive mode before creating the volume
-set.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) addvolentry</B> command to define volume entries
-in an existing volume set. The Backup System assigns each volume entry
-an index within the volume set, starting with 1 (one).
-<PRE> backup> <B>addvolentry -name</B> <<VAR>volume set name</VAR>> \
- <B>-server</B> <<VAR>machine name</VAR>> \
- <B>-partition</B> <<VAR>partition name</VAR>> \
- <B>-volumes</B> <<VAR>volume name (regular expression)</VAR>>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>addvole
-</B><DD>Is the shortest acceptable abbreviation of <B>addvolentry</B>.
-<P><DT><B>-name
-</B><DD>Names the volume set to which to add the volume entry. It must
-already exist (use the <B>backup addvolset</B> command to create
-it).
-<P><DT><B>-server
-</B><DD>Defines the set of one or more file server machines that house the volumes
-in the volume entry. Provide either one fully-qualified hostname (such
-as <B>fs1.abc.com</B>) or the metacharacter expression
-<B>.*</B> (period and asterisk), which matches all machine names in
-the VLDB.
-<P><DT><B>-partition
-</B><DD>Defines the set of one or more partitions that house the volumes in the
-volume entry. Provide either one complete partition name (such as
-<B>/vicepa</B>) or the metacharacter expression <B>.*</B>
-(period and asterisk), which matches all partition names.
-<P><DT><B>-volumes
-</B><DD>Defines the set of one or more volumes included in the volume entry,
-identifying them by name. This argument can include a combination of
-alphanumeric characters and one or more of the metacharacter expressions
-discussed in the introductory material in this section.
-</DL>
-</OL>
-<A NAME="IDX6884"></A>
-<A NAME="IDX6885"></A>
-<A NAME="IDX6886"></A>
-<A NAME="IDX6887"></A>
-<A NAME="IDX6888"></A>
-<A NAME="IDX6889"></A>
-<P><H3><A NAME="HDRWQ365" HREF="auagd002.htm#ToC_293">To display volume sets and volume entries</A></H3>
-<OL TYPE=1>
-<P><LI>Issue the <B>backup listvolsets</B> command to display the volume
-entries in a specific volume set or all of them. If you are displaying
-a temporary volume set, you must still be in the interactive session in which
-you created it.
-<PRE> % <B>backup listvolsets</B> [<<VAR>volume set name</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>listv
-</B><DD>Is the shortest acceptable abbreviation of <B>listvolsets</B>.
-<P><DT><B><VAR>volume set name</VAR>
-</B><DD>Names the volume set to display. Omit this argument to display all
-defined volume sets.
-</DL>
-<P>The output from the command uses the wildcard notation used when the volume
-entries were created. The string <TT>(temporary)</TT> marks a
-temporary volume set. The following example displays all three of the
-volume sets defined in a cell's Backup Database, plus a temporary volume
-set <B>pat+jones</B> created during the current interactive session:
-<P>
-<PRE> backup> <B>listv</B>
- Volume set pat+jones (temporary):
- Entry 1: server fs1.abc.com, partition /vicepe, volumes: user.pat.backup
- Entry 2: server fs5.abc.com, partition /viceph, volumes: user.jones.backup
- Volume set user:
- Entry 1: server .*, partition .*, volumes: user.*\.backup
- Volume set sun:
- Entry 1: server .*, partition .*, volumes: sun4x_55\..*
- Entry 2: server .*, partition .*, volumes: sun4x_56\..*
- Volume set rs:
- Entry 1: server .*, partition .*, volumes: rs_aix42\..*
-</PRE>
-</OL>
-<A NAME="IDX6890"></A>
-<A NAME="IDX6891"></A>
-<A NAME="IDX6892"></A>
-<A NAME="IDX6893"></A>
-<P><H3><A NAME="Header_294" HREF="auagd002.htm#ToC_294">To delete a volume set</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Issue the <B>backup delvolset</B> command to delete one or more volume
-sets and all of the component volume entries in them. If you are
-deleting a temporary volume set, you must still be in the interactive session
-in which you created it.
-<PRE> % <B>backup delvolset</B> <<VAR>volume set name</VAR>><SUP>+</SUP>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>delvols
-</B><DD>Is the shortest acceptable abbreviation of <B>delvolset</B>.
-<P><DT><B><VAR>volume set name</VAR>
-</B><DD>Names each volume set to delete.
-</DL>
-</OL>
-<A NAME="IDX6894"></A>
-<A NAME="IDX6895"></A>
-<A NAME="IDX6896"></A>
-<A NAME="IDX6897"></A>
-<A NAME="IDX6898"></A>
-<P><H3><A NAME="Header_295" HREF="auagd002.htm#ToC_295">To delete a volume entry from a volume set</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Issue the <B>backup</B> command to enter interactive mode.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>If the volume set includes more than one volume entry, issue the
-<B>(backup) listvolsets</B> command to display the index number associated
-with each one (if there is only one volume entry, its index is 1). For
-a more detailed description of the command's output, see <A HREF="#HDRWQ365">To display volume sets and volume entries</A>.
-<PRE> backup> <B>listvolsets</B> <<VAR>volume set name</VAR>>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>listv
-</B><DD>Is the shortest acceptable abbreviation of <B>listvolsets</B>.
-<P><DT><B><VAR>volume set name</VAR>
-</B><DD>Names the volume set for which to display volume entries.
-</DL>
-<P><LI>Issue the <B>(backup) delvolentry</B> command to delete the volume
-entry.
-<PRE> backup> <B>delvolentry</B> <<VAR>volume set name</VAR>> <<VAR>volume entry index</VAR>>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>delvole
-</B><DD>Is the shortest acceptable abbreviation of <B>delvolentry</B>.
-<P><DT><B><VAR>volume set name</VAR>
-</B><DD>Names the volume set from which to delete a volume entry.
-<P><DT><B><VAR>volume entry index</VAR>
-</B><DD>Specifies the index number of the volume entry to delete.
-</DL>
-</OL>
-<HR><H2><A NAME="HDRWQ366" HREF="auagd002.htm#ToC_296">Defining and Displaying the Dump Hierarchy</A></H2>
-<A NAME="IDX6899"></A>
-<A NAME="IDX6900"></A>
-<P>A dump hierarchy is a logical structure in the Backup Database that defines
-the relationship between full and incremental dumps; that is, it defines
-which dump serves as the parent for an incremental dump. Each
-individual component of a hierarchy is a dump level.
-<P>As you define dump levels with the <B>backup adddump</B> command, keep
-the following rules and suggestions in mind:
-<UL>
-<P><LI>Each full dump level is the top level of a hierarchy. You can
-create as many hierarchies as you need to dump different volume sets on
-different schedules.
-<P><LI>The name of a full dump level consists of an initial slash (<B>/</B>),
-followed by a string of up to 28 alphanumeric characters.
-<P><LI>The name of an incremental dump level resembles a pathname, starting with
-the name of a full dump level, then the first incremental level, and so on,
-down to the final incremental level. Precede each level name with a
-slash to separate it from the preceding level. Like the full level,
-each component level in the name can have up to 28 alphanumeric characters,
-not including the slash.
-<P><LI>A hierarchy can have any have any number of levels, but the maximum length
-of a complete dump level name is 256 characters, including the slashes.
-<P><LI>Before defining a given incremental level, you must define all of the
-levels above it in the hierarchy.
-<P><LI>Do not use the period (<B>.</B>) in dump level names.
-The Backup System uses the period as the separator between a dump's
-volume set name and dump level name when it creates the dump name and AFS tape
-name. Any other alphanumeric and punctuation characters are allowed,
-but it is best to avoid metacharacters. If you include a metacharacter,
-you must precede it with a backslash (<B>\</B>) or surround the entire
-dump level name with double quotes (<B>" "</B>).
-<P><LI>Naming dump levels for days or other actual time points reminds you when
-to perform dumps, and makes it easier to track the relationship between dumps
-performed at different levels. However, the names have no meaning to
-the Backup System: it does not automatically create dumps according to
-the names, and does not prevent you from, for example, using the
-<B>/sunday</B> level when creating a dump on a Tuesday.
-<P><LI>It is best not to use the same name for more than one component level in a
-hierarchy, because it means the resulting dump name no longer indicates which
-level was used. For example, if you name a dump level
-<B>/full/incr/incr</B>, then the dump name and AFS tape name that result
-from dumping a volume set at the first incremental level
-(<B>/full/incr</B>) look the same as the names that result from dumping at
-the second incremental level (<B>/full/incr/incr</B>).
-<P><LI>Individual levels in different hierarchies can have the same name, but the
-complete pathnames must be unique. For example,
-<B>/sunday1/monday</B> and <B>/sunday2/monday</B> share the same name
-at the final level, but are unique because they have different names at the
-full level (belong to different hierarchies). However, using the same
-name in multiple hierarchies means that dump and AFS tape names do not
-unambiguously indicate which hierarchy was used.
-</UL>
-<P>The following example shows three hierarchies. Each begins with a
-full dump at the top: <B>sunday1</B> for the first hierarchy,
-<B>sunday2</B> for the second hierarchy, and <B>sunday_bin</B> for the
-third hierarchy. In all three hierarchies, each of the other dump
-levels is an incremental level.
-<PRE> /sunday1
- /monday
- /tuesday
- /wednesday
- /thursday
- /friday
- /sunday2
- /monday
- /tuesday
- /wednesday
- /thursday
- /friday
- /sunday_bin
- /monday
- /wednesday
- /friday
-</PRE>
-<P>In the first hierarchy, each incremental dump level refers to the full
-level <B>/sunday1</B> as its parent. When (for example) you dump a
-volume set at the <B>/sunday1/wednesday</B> level, it includes data that
-has changed since the volume set was dumped at the <B>/sunday1</B>
-level.
-<P>In contrast, each incremental dump level in the second hierarchy refers to
-the immediately preceding dump level as its parent. When you dump a
-volume set at the corresponding level in the second hierarchy
-(<B>/sunday2/monday/tuesday/wednesday</B>), the dump includes only data
-that has changed since the volume set was dumped at the
-<B>/sunday2/monday/tuesday</B> level (presumably the day before).
-Assuming you create dumps on the indicated days, an incremental dump made
-using this hierarchy contains less data than an incremental dump made at the
-corresponding level in the first hierarchy.
-<P>The third hierarchy is more appropriate for dumping volumes for which a
-daily backup is excessive because the data does not change often (for example,
-system binaries).
-<P><H3><A NAME="HDRWQ367" HREF="auagd002.htm#ToC_297">Creating a Tape Recycling Schedule</A></H3>
-<A NAME="IDX6901"></A>
-<A NAME="IDX6902"></A>
-<A NAME="IDX6903"></A>
-<A NAME="IDX6904"></A>
-<A NAME="IDX6905"></A>
-<A NAME="IDX6906"></A>
-<A NAME="IDX6907"></A>
-<A NAME="IDX6908"></A>
-<P>If your cell is like most cells, you have a limited amount of room for
-storing backup tapes and a limited budget for new tapes. The easiest
-solution is to recycle tapes by overwriting them when you no longer need the
-backup data on them. The Backup System helps you implement a recycling
-schedule by enabling you to associate an expiration date with each dump
-level. The expiration date defines when a dump created at that level
-expires. Until that time the Backup System refuses to overwrite a tape
-that contains the dump. Thus, assigning expiration dates automatically
-determines how you recycle tapes.
-<P>When designing a tape-recycling schedule, you must decide how far in the
-past and to what level of precision you want to guarantee access to backed up
-data. For instance, if you decide to guarantee that you can restore a
-user's home volume to its state on any given day in the last two weeks,
-you cannot recycle the tape that contains a given daily dump for at least two
-weeks after you create it. Similarly, if you decide to guarantee that
-you can restore home volumes to their state at the beginning of any given week
-in the last month, you cannot recycle the tapes in a dump set containing a
-weekly dump for at least four weeks. The following example dump
-hierarchy implements this recycling schedule by setting the expiration date
-for each daily incremental dump to 13 days and the expiration date of the
-weekly full dumps to 27 days.
-<P>The tapes used to store dumps created at the daily incremental levels in
-the <B>/sunday1</B> hierarchy expire just in time to be recycled for daily
-dumps in the <B>/sunday3</B> hierarchy (and vice versa), and there is a
-similar relationship between the <B>/sunday2</B> and <B>/sunday4</B>
-hierarchies. Similarly, the tape that houses a full dump at the
-<B>/sunday1</B> level expires just in time to be used for a full dump on
-the first Sunday of the following month.
-<PRE>
- /sunday1 expires in 27d
- /monday1 expires in 13d
- /tuesday1 expires in 13d
- /wednesday1 expires in 13d
- /thursday1 expires in 13d
- /friday1 expires in 13d
- /sunday2 expires in 27d
- /monday2 expires in 13d
- /tuesday2 expires in 13d
- /wednesday2 expires in 13d
- /thursday2 expires in 13d
- /friday2 expires in 13d
- /sunday3 expires in 27d
- /monday1 expires in 13d
- /tuesday1 expires in 13d
- /wednesday1 expires in 13d
- /thursday1 expires in 13d
- /friday1 expires in 13d
- /sunday4 expires in 27d
- /monday2 expires in 13d
- /tuesday2 expires in 13d
- /wednesday2 expires in 13d
- /thursday2 expires in 13d
- /friday2 expires in 13d
-</PRE>
-<P>If you use appended dumps in your cell, keep in mind that all dumps in a
-dump set are subject to the latest (furthest into the future) expiration date
-associated with any of the constituent dumps. You cannot recycle any of
-the tapes that contain a dump set until all of the dumps have reached their
-expiration date. See also <A HREF="auagd012.htm#HDRWQ414">Appending Dumps to an Existing Dump Set</A>.
-<P>Most tape manufacturers recommend that you write to a tape a limited number
-of times, and it is best not to exceed this limit when recycling tapes.
-To help you track tape usage, the Backup System records a <TT>useCount</TT>
-counter on the tape's label. It increments the counter each time
-the tape's label is rewritten (each time you use the <B>backup
-labeltape</B> or <B>backup dump</B> command). To display the
-<TT>useCount</TT> counter, use the <B>backup readlabel</B> or
-<B>backup scantape</B> command or include the <B>-id</B> and
-<B>-verbose</B> options when you issue the <B>backup dumpinfo</B>
-command. For instructions see <A HREF="#HDRWQ371">Writing and Reading Tape Labels</A> or <A HREF="auagd012.htm#HDRWQ417">Displaying Backup Dump Records</A>.
-<A NAME="IDX6909"></A>
-<A NAME="IDX6910"></A>
-<A NAME="IDX6911"></A>
-<A NAME="IDX6912"></A>
-<P><H3><A NAME="HDRWQ368" HREF="auagd002.htm#ToC_298">Archiving Tapes</A></H3>
-<A NAME="IDX6913"></A>
-<A NAME="IDX6914"></A>
-<P>Even if you make extensive use of tape recycling, there is probably some
-backup data that you need to archive for a long (or even an indefinite) period
-of time. You can use the Backup System to archive data on a regular
-schedule, and you can also choose to archive data on tapes that you previously
-expected to recycle.
-<P>If you want to archive data on a regular basis, you can create
-date-specific dump levels in the dump hierarchy. For example, if you
-decide to archive a full dump of all data in your cell at the beginning of
-each quarter in the year 2000, you can define the following levels in the dump
-hierarchy:
-<PRE> /1Q2000
- /2Q2000
- /3Q2000
- /4Q2000
-</PRE>
-<P>If you decide to archive data that is on tapes you previously planned to
-recycle, you must gather all of the tapes that contain the relevant dumps,
-both full and incremental. To avoid accidental erasure, it is best to
-set the switch on the tapes that makes them read-only, before placing them in
-your archive storage area. If the tapes also contain a large amount of
-extraneous data that you do not want to archive, you can restore just the
-relevant data into a new temporary volume, and back up that volume to the
-smallest number of tapes possible. One reason to keep a dump set small
-is to minimize the amount of irrelevant data in a dump set you end up needing
-to archive.
-<P>If you do not expect to restore archived data to the file system, you can
-consider using the <B>backup deletedump</B> command to remove the
-associated dump records from the Backup Database, which helps keep it to an
-efficient size. If you ever need to restore the data, you can use the
-<B>-dbadd</B> flag to the <B>backup scantape</B> command to reinsert
-the dump records into the database. For instructions, see <A HREF="auagd012.htm#HDRWQ420">To scan the contents of a tape</A>.
-<P><H3><A NAME="HDRWQ369" HREF="auagd002.htm#ToC_299">Defining Expiration Dates</A></H3>
-<P>To associate an expiration date with a dump level as you
-create it, use the <B>-expires</B> argument to the <B>backup
-adddump</B> command. To change an existing dump level's
-expiration date, use the <B>-expires</B> argument to the <B>backup
-setexp</B> command. (Note that it is not possible to change the
-expiration date of an actual dump that has already been created at that
-level). With both commands, you can define an expiration date either in
-absolute terms (for example, 13 January 2000) or relative terms (for example,
-30 days from when the dump is created).
-<UL>
-<P><LI>To define an absolute expiration date, provide a value for the
-<B>-expires</B> argument with the following format:
-<PRE> [<B>at</B>] <VAR>mm</VAR><B>/</B><VAR>dd</VAR><B>/</B><VAR>yyyy</VAR> [<VAR>hh</VAR><B>:</B><VAR>MM</VAR>]
-</PRE>
-<P>where <VAR>mm</VAR> indicates the month, <VAR>dd</VAR> the day, and
-<VAR>yyyy</VAR> the year when the dump expires. Valid values for the year
-fall in the range <B>1970</B> through <B>2037</B> (the latest possible
-date that the UNIX time representation can express is in early 2038).
-If you provide a time, it must be in 24-hour format with <VAR>hh</VAR> the hours
-and <VAR>MM</VAR> the minutes (for example, <B>21:50</B> is 9:50
-p.m.). If you omit the time, the default is 00:00
-hours (12:00 midnight) on the indicated date.
-<P><LI>To define a relative expiration date, provide a value for the
-<B>-expires</B> argument with the following format:
-<PRE> [<B>in</B>] [<VAR>years</VAR><B>y</B>] [<VAR>months</VAR><B>m</B>] [<VAR>days</VAR><B>d</B>]
-</PRE>
-<P>where each of <VAR>years</VAR>, <VAR>months</VAR>, and <VAR>days</VAR> is an
-integer. Provide at least one of them together with the corresponding
-units letter (<B>y</B>, <B>m</B>, or <B>d</B> respectively), with
-no intervening space. If you provide more than one of the three, list
-them in the indicated order.
-<P>The Backup System calculates a dump's actual expiration date by adding
-the indicated relative value to the start time of the dump operation.
-For example, it assigns an expiration date 1 year, 6 months, and 2 days in the
-future to a dump created at a dump level with associated expiration date
-<B>in 1y 6m 2d</B>.
-<P><LI>To indicate that a dump backed up at the corresponding dump level never
-expires, provide the value <B>NEVER</B> instead of a date and time.
-To recycle tapes that contain dumps created at such a level, you must use the
-<B>backup readlabel</B> command to overwrite the tape's label.
-</UL>
-<P>If you omit the <B>-expires</B> argument to the <B>backup
-adddump</B> command, then the expiration date is set to UNIX time zero
-(00:00 hours on 1 January 1970). The Backup System considers
-dumps created at such a dump level to expire at their creation time. If
-no dumps in a dump set have an expiration date, then the Backup System does
-not impose any restriction on recycling the tapes that contain the dump
-set. If you need to prevent premature recycling of the tapes that
-contain the dump set, you must use a manual tracking system.
-<A NAME="IDX6915"></A>
-<A NAME="IDX6916"></A>
-<A NAME="IDX6917"></A>
-<A NAME="IDX6918"></A>
-<A NAME="IDX6919"></A>
-<A NAME="IDX6920"></A>
-<A NAME="IDX6921"></A>
-<A NAME="IDX6922"></A>
-<A NAME="IDX6923"></A>
-<P><H3><A NAME="Header_300" HREF="auagd002.htm#ToC_300">To add a dump level to the dump hierarchy</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>backup adddump</B> command to define one or more dump
-levels. If you are defining an incremental level, then all of the
-parent levels that precede it in its pathname must either already exist or
-precede it on the command line.
-<PRE> backup> <B>adddump -dump</B> <<VAR>dump level name</VAR>><SUP>+</SUP> [<B>-expires</B> <<VAR>expiration date</VAR>><SUP>+</SUP>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>addd
-</B><DD>Is the shortest acceptable abbreviation of <B>adddump</B>.
-<P><DT><B>-dump
-</B><DD>Names each dump level to added. If you specify more than one dump
-level name, you must include the <B>-dump</B> switch.
-<P>Provide the entire pathname of the dump level, preceding each level in the
-pathname with a slash (<B>/</B>). Each component level can be up to
-28 characters in length, and the pathname can include up to 256 characters
-including the slashes.
-<P><DT><B>-expires
-</B><DD>Sets the expiration date associated with each dump level. Specify
-either a relative or absolute expiration date, as described in <A HREF="#HDRWQ369">Defining Expiration Dates</A>, or omit this argument to assign no expiration date to the
-dump levels.
-<TABLE><TR><TD ALIGN="LEFT" VALIGN="TOP"><B>Note:</B></TD><TD ALIGN="LEFT" VALIGN="TOP">A plus sign follows this argument in the command's syntax statement
-because it accepts a multiword value which does not need to be enclosed in
-double quotes or other delimiters, not because it accepts multiple
-dates. Provide only one date (and optionally, time) definition to be
-associated with each dump level specified by the <B>-dump</B>
-argument.
-</TD></TR></TABLE>
-</DL>
-</OL>
-<A NAME="IDX6924"></A>
-<A NAME="IDX6925"></A>
-<A NAME="IDX6926"></A>
-<A NAME="IDX6927"></A>
-<A NAME="IDX6928"></A>
-<A NAME="IDX6929"></A>
-<P><H3><A NAME="Header_301" HREF="auagd002.htm#ToC_301">To change a dump level's expiration date</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) setexp</B> command to change the expiration date
-associated with one or more dump levels.
-<PRE> backup> <B>setexp -dump</B> <<VAR>dump level name</VAR>><SUP>+</SUP> [<B>-expires</B> <<VAR>expiration date</VAR>><SUP>+</SUP>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>se
-</B><DD>Is the shortest acceptable abbreviation of <B>setexp</B>.
-<P><DT><B>-dump
-</B><DD>Names each existing dump level for which to change the expiration
-date.
-<P><DT><B>-expires
-</B><DD>Sets the expiration date associated with each dump level. Specify
-either a relative or absolute expiration date, as described in <A HREF="#HDRWQ369">Defining Expiration Dates</A>; omit this argument to remove the expiration date
-currently associated with each dump level.
-<TABLE><TR><TD ALIGN="LEFT" VALIGN="TOP"><B>Note:</B></TD><TD ALIGN="LEFT" VALIGN="TOP">A plus sign follows this argument in the command's syntax statement
-because it accepts a multiword value which does not need to be enclosed in
-double quotes or other delimiters, not because it accepts multiple
-dates. Provide only one date (and optionally, time) definition to be
-associated with each dump level specified by the <B>-dump</B>
-argument.
-</TD></TR></TABLE>
-</DL>
-</OL>
-<A NAME="IDX6930"></A>
-<A NAME="IDX6931"></A>
-<A NAME="IDX6932"></A>
-<A NAME="IDX6933"></A>
-<A NAME="IDX6934"></A>
-<P><H3><A NAME="Header_302" HREF="auagd002.htm#ToC_302">To delete a dump level from the dump hierarchy</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) deldump</B> command to delete the dump
-level. Note that the command automatically removes all incremental dump
-levels for which the specified level serves as parent, either directly or
-indirectly.
-<PRE> backup> <B>deldump</B> <<VAR>dump level name</VAR>>
-</PRE>
-<P>where
-<DL>
-<P><DT><B>deld
-</B><DD>Is the shortest acceptable abbreviation of <B>deldump</B>.
-<P><DT><B><VAR>dump level name</VAR>
-</B><DD>Specifies the complete pathname of the dump level to delete.
-</DL>
-</OL>
-<A NAME="IDX6935"></A>
-<A NAME="IDX6936"></A>
-<A NAME="IDX6937"></A>
-<A NAME="IDX6938"></A>
-<A NAME="IDX6939"></A>
-<A NAME="IDX6940"></A>
-<P><H3><A NAME="HDRWQ370" HREF="auagd002.htm#ToC_303">To display the dump hierarchy</A></H3>
-<OL TYPE=1>
-<P><LI>Issue the <B>backup listdumps</B> command to display the dump
-hierarchy.
-<PRE> % <B>backup listdumps</B>
-</PRE>
-<P>where <B>listd</B> is the shortest acceptable abbreviation of
-<B>listdumps</B>.
-<P>The output from this command displays the dump hierarchy, reporting the
-expiration date associated with each dump level, as in the following
-example.
-<PRE> % <B>backup listdumps</B>
- /week1 expires in 27d
- /tuesday expires in 13d
- /thursday expires in 13d
- /sunday expires in 13d
- /tuesday expires in 13d
- /thursday expires in 13d
- /week3 expires in 27d
- /tuesday expires in 13d
- /thursday expires in 13d
- /sunday expires in 13d
- /tuesday expires in 13d
- /thursday expires in 13d
- sunday1 expires in 27d
- /monday1 expires in 13d
- /tuesday1 expires in 13d
- /wednesday1 expires in 13d
- /thursday1 expires in 13d
- /friday1 expires in 13d
- sunday2 expires in 27d
- /monday2 expires in 13d
- /tuesday2 expires in 13d
- /wednesday2 expires in 13d
- /thursday2 expires in 13d
- /friday2 expires in 13d
- sunday3 expires in 27d
- /monday1 expires in 13d
- /tuesday1 expires in 13d
- /wednesday1 expires in 13d
- /thursday1 expires in 13d
- /friday1 expires in 13d
- sunday4 expires in 27d
- /monday2 expires in 13d
- /tuesday2 expires in 13d
- /wednesday2 expires in 13d
- /thursday2 expires in 13d
- /friday2 expires in 13d
-</PRE>
-</OL>
-<HR><H2><A NAME="HDRWQ371" HREF="auagd002.htm#ToC_304">Writing and Reading Tape Labels</A></H2>
-<A NAME="IDX6941"></A>
-<A NAME="IDX6942"></A>
-<A NAME="IDX6943"></A>
-<A NAME="IDX6944"></A>
-<A NAME="IDX6945"></A>
-<A NAME="IDX6946"></A>
-<P>As described in <A HREF="#HDRWQ352">Dump Names and Tape Names</A> and <A HREF="#HDRWQ353">Tape Labels, Dump Labels, and EOF Markers</A>, you can assign either a permanent name or
-an AFS tape name to a tape that you use in the Backup System. The names
-are recorded on the tape's magnetic label, along with an indication of
-the tape's capacity (size).
-<P>You can assign either a permanent name or an AFS tape name, but not
-both. In general, assigning permanent names rather than AFS tape names
-simplifies the backup process, because the Backup System does not dictate the
-format of permanent names. If a tape does not have a permanent name,
-then by default the Backup System accepts only three strictly defined values
-in the AFS tape name field, and refuses to write a dump to a tape with an
-inappropriate AFS tape name. The acceptable values are a name that
-matches the volume set and dump level of the initial dump, the value
-<TT><NULL></TT>, and no value in the field at all.
-<P>If a tape has a permanent name, the Backup System does not check the AFS
-tape name, and as part of the dump operation constructs the appropriate AFS
-tape name itself and records it on the label. This means that if you
-assign a permanent name, the Backup System assigns an AFS tape name itself and
-the tape has both types of name. In contrast, if a tape has an AFS tape
-name but not a permanent name, you cannot assign a permanent name without
-first erasing the AFS tape name.
-<P>(You can also suppress the Backup System's check of a tape's AFS
-tape name, even it does not have a permanent name, by assigning the value
-<B>NO</B> to the <B>NAME_CHECK</B> instruction in the device
-configuration file. See <A HREF="#HDRWQ379">Eliminating the AFS Tape Name Check</A>.)
-<P>Because the Backup System accepts unlabeled tapes, you do not have to label
-a tape before using it for the first time. After the first use, there
-are a couple of cases in which you must relabel a tape in order to write a
-dump to it:
-<UL>
-<P><LI>The tape does not have a permanent name, and the AFS tape name on it does
-not match the new initial dump set you want to create (the volume set and dump
-level names are different, or the index is incorrect).
-<P><LI>You want to recycle a tape before all of the dumps on it have
-expired. The Backup System does not overwrite a tape with any unexpired
-dumps. Keep in mind, though, that if you relabel the tape to making
-recycling possible, you erase all the dump records for the tape from the
-Backup Database, which makes it impossible to restore any data from the
-tape.
-</UL>
-<TABLE><TR><TD ALIGN="LEFT" VALIGN="TOP"><B>Note:</B></TD><TD ALIGN="LEFT" VALIGN="TOP">Labeling a tape that contains dump data makes it impossible to use that data
-in a restore operation, because the labeling operation removes the dump's
-records from the Backup Database. If you want to record a permanent
-name on a tape label, you must do it before dumping any data to the
-tape.
-</TD></TR></TABLE>
-<P><H3><A NAME="Header_305" HREF="auagd002.htm#ToC_305">Recording a Name on the Label</A></H3>
-<P>To write a permanent name on a tape's label, include the
-<B>-pname</B> argument to specify a string of up to 32 characters.
-Check that no other tape used with the Backup System in your cell already has
-the permanent name you are assigning, because the Backup System does not
-prevent you from assigning the same name to multiple tapes. The Backup
-System overwrites the existing AFS tape name, if any, with the value
-<TT><NULL></TT>. When a tape has a permanent name, the Backup
-System uses it instead of the AFS tape name in most prompts and when referring
-to the tape in output from <B>backup</B> commands. The permanent
-name persists until you again include the <B>-pname</B> argument to the
-<B>backup labeltape</B> command, regardless of the tape's contents
-and of how often you recycle the tape or use the <B>backup labeltape</B>
-command without the <B>-pname</B> argument.
-<P>To write an AFS tape name on the label, provide a value for the
-<B>-name</B> argument that matches the volume set name and the final
-element in the dump level pathname of the initial dump that you plan to write
-to the tape, and an index that indicates the tape's place in the sequence
-of tapes for the dump set. The format is as follows:
-<PRE> <VAR>volume_set_name</VAR><B>.</B><VAR>dump_level_name</VAR><B>.</B><VAR>tape_index</VAR>
-</PRE>
-<P>If you omit the <B>-name</B> argument, the Backup System sets the AFS
-tape name to <TT><NULL></TT>. The Backup System automatically
-constructs and records the appropriate name when you later write an initial
-dump to the tape by using the <B>backup dump</B> or <B>backup
-savedb</B> command.
-<P>You cannot use the <B>-name</B> argument if the tape already has a
-permanent name. To erase a tape's permanent name, provide a null
-value to the <B>-pname</B> argument by issuing the following
-command:
-<PRE> % <B>backup labeltape -pname ""</B>
-</PRE>
-<P><H3><A NAME="Header_306" HREF="auagd002.htm#ToC_306">Recording a Capacity on the Label</A></H3>
-<P>To record the tape's capacity on the label, specify a number of
-kilobytes as the <B>-size</B> argument. If you omit this argument
-the first time you label a tape, the Backup System records the default tape
-capacity associated with the specified port offset in the
-<B>/usr/afs/backup/tapeconfig</B> file on the Tape Coordinator
-machine. If the tape's capacity is different (in particular,
-larger) than the capacity recorded in the <B>tapeconfig</B> file, it is
-best to record a capacity on the label before using the tape. Once set,
-the value in the label's capacity field persists until you again use the
-<B>-size</B> argument to the <B>backup labeltape</B> command.
-For a discussion of the appropriate capacity to record for tapes, see <A HREF="#HDRWQ357">Configuring the tapeconfig File</A>.
-<P>To read a tape's label, use the <B>backup readlabel</B>
-command.
-<P>Most tapes also come with an adhesive label you can apply to the exterior
-casing. To help you easily identify a tape, record at least the
-tape's permanent and AFS tape names on the adhesive label.
-Depending on the recycling scheme you use, it can be useful to record other
-information, such as the dump ID, dump creation date, and expiration date of
-each dump you write to the tape.
-<A NAME="IDX6947"></A>
-<A NAME="IDX6948"></A>
-<P><H3><A NAME="HDRWQ372" HREF="auagd002.htm#ToC_307">To label a tape</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>If the Tape Coordinator for the tape device that is to perform the
-operation is not already running, open a connection to the appropriate Tape
-Coordinator machine and issue the <B>butc</B> command, for which complete
-instructions appear in <A HREF="auagd012.htm#HDRWQ407">To start a Tape Coordinator process</A>.
-<PRE> % <B>butc</B> [<<VAR>port offset</VAR>>] [<B>-noautoquery</B>]
-</PRE>
-<P><LI>Place the tape in the device.
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode, if you want to label multiple tapes or issue additional
-commands after labeling the tape. The interactive prompt appears in the
-following step.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) labeltape</B> command to label the tape.
-<PRE> backup> <B>labeltape</B> [<B>-name</B> <<VAR>tape name, defaults to NULL</VAR>>] \
- [<B>-size</B> <<VAR>tape size in Kbytes, defaults to size in tapeconfig</VAR>>] \
- [<B>-portoffset</B> <<VAR>TC port offset</VAR>>] [<B>-pname</B> <<VAR>permanent tape name</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>la
-</B><DD>Is the shortest acceptable abbreviation of <B>labeltape</B>.
-<P><DT><B>-name
-</B><DD>Specifies the AFS tape name to record on the label. Include this
-argument or the <B>-pname</B> argument, but not both. If you omit
-this argument, the AFS tape name is set to <TT><NULL></TT>. If you
-provide it, it must have the following format.
-<PRE><VAR>volume_set_name</VAR><B>.</B><VAR>dump_level_name</VAR><B>.</B><VAR>tape_index</VAR>
-</PRE>
-<P>
-<P>for the tape to be acceptable for use in a future <B>backup dump</B>
-operation. The <VAR>volume_set_name</VAR> must match the volume set name
-of the initial dump to be written to the tape, <VAR>dump_level_name</VAR> must
-match the last element of the dump level pathname at which the volume set is
-to be dumped, and <VAR>tape_index</VAR> must correctly indicate the tape's
-place in the sequence of tapes that house the dump set; indexing begins
-with the number 1 (one).
-<P><DT><B>-size
-</B><DD>Specifies the tape capacity to record on the label. If you are
-labeling the tape for the first time, you need to include this argument only
-if the tape's capacity differs from the capacity associated with the
-specified port offset in the <B>/usr/afs/backup/tapeconfig</B> file on the
-Tape Coordinator machine.
-<P>If you provide a value, it is an integer value followed by a letter that
-indicates units, with no intervening space. A unit value of
-<B>k</B> or <B>K</B> indicates kilobytes, <B>m</B> or <B>M</B>
-indicates megabytes, and <B>g</B> or <B>G</B> indicates
-gigabytes. If you omit the units letter, the default is
-kilobytes.
-<P><DT><B>-portoffset
-</B><DD>Specifies the port offset number of the Tape Coordinator handling the tape
-or backup data file for this operation. You must provide this argument
-unless the default value of <B>0</B> (zero) is appropriate.
-<P><DT><B>-pname
-</B><DD>Specifies the permanent name to record on the label. It can be up
-to 32 characters in length, and include any alphanumeric characters.
-Avoid metacharacters that have a special meaning to the shell, to avoid having
-to mark them as literal in commands issued at the shell prompt.
-<P>Include this argument or the <B>-name</B> argument, but not
-both. When you provide this argument, the AFS tape name is set to
-<TT><NULL></TT>. If you omit this argument, any existing permanent
-name is retained.
-</DL>
-<P><LI>If you did not include the <B>-noautoquery</B> flag when you issued
-the <B>butc</B> command, or if the device's device configuration file
-includes the instruction <B>AUTOQUERY YES</B>, then the Tape Coordinator
-prompts you to place the tape in the device's drive. You have
-already done so, but you must now press <B><Return></B> to indicate
-that the tape is ready for labeling.
-</OL>
-<A NAME="IDX6949"></A>
-<A NAME="IDX6950"></A>
-<P><H3><A NAME="HDRWQ373" HREF="auagd002.htm#ToC_308">To read the label on a tape</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>If the Tape Coordinator for the tape device that is to perform the
-operation is not already running, open a connection to the appropriate Tape
-Coordinator machine and issue the <B>butc</B> command, for which complete
-instructions appear in <A HREF="auagd012.htm#HDRWQ407">To start a Tape Coordinator process</A>.
-<PRE> % <B>butc</B> [<<VAR>port offset</VAR>>] [<B>-noautoquery</B>]
-</PRE>
-<P><LI>Place the tape in the device.
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode, if you want to label multiple tapes or issue additional
-commands after labeling the tape. The interactive prompt appears in the
-following step.
-<PRE> % <B>backup</B>
-</PRE>
-<P><LI>Issue the <B>(backup) readlabel</B> command to read the label on the
-tape.
-<PRE> backup> <B>readlabel</B> [<<VAR>TC port offset</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>rea
-</B><DD>Is the shortest acceptable abbreviation of <B>readlabel</B>.
-<P><DT><B><VAR>TC port offset</VAR>
-</B><DD>Specifies the port offset number of Tape Coordinator handling the tape or
-backup data file for this operation. You must provide this argument
-unless the default value of <B>0</B> (zero) is appropriate.
-</DL>
-<P><LI>If you did not include the <B>-noautoquery</B> flag when you issued
-the <B>butc</B> command, or the device's device configuration file
-includes the instruction <B>AUTOQUERY YES</B> instruction, then the Tape
-Coordinator prompts you to place the tape in the device's drive.
-You have already done so, but you must now press <B><Return></B> to
-indicate that the tape is ready for reading.
-</OL>
-<P>Information from the tape label appears both in the <B>backup</B>
-command window and in the Tape Coordinator window. The output in the
-command window has the following format:
-<PRE> Tape read was labelled: <VAR>tape_name</VAR> (<VAR>initial_dump_ID</VAR>)
- size: <VAR>size</VAR> KBytes
-</PRE>
-<P>where <VAR>tape_name</VAR> is the tape's permanent name (if it has one)
-or AFS tape name, <VAR>initial_dump_ID</VAR> is the dump ID of the initial dump
-on the tape, and <VAR>size</VAR> is the capacity recorded on the label, in
-kilobytes.
-<P>The information in the Tape Coordinator window is more extensive.
-The tape's permanent name appears in the <TT>tape name</TT> field and
-its AFS tape name in the <TT>AFS tape name</TT> field. If either name
-is undefined, a value of <TT><NULL></TT> appears in the field
-instead. The capacity recorded on the label appears in the
-<TT>size</TT> field. Other fields in the output report the creation
-time, dump level name, and dump ID of the initial dump on the tape
-(<TT>creationTime</TT>, <TT>dump path</TT>, and <TT>dump id</TT>
-respectively). The <TT>cell</TT> field reports the cell in which the
-dump operation was performed, and the <TT>useCount</TT> field reports the
-number of times the tape has been relabeled, either with the <B>backup
-labeltape</B> command or during a dump operation. For further
-details, see the command's reference page in the <I>AFS Administration
-Reference</I>.
-<P>If the tape has no label, or if the drive is empty, the following message
-appears at the command shell:
-<PRE> Failed to read tape label.
-</PRE>
-<P>The following example illustrates the output in the command shell for a
-tape in the device with port offset 1:
-<PRE> % <B>backup readlabel 1</B>
- Tape read was labelled: monthly_guest (917860000)
- size: 2150000 KBytes
-</PRE>
-<P>The following output appears in the Tape Coordinator window at the same
-time:
-<PRE> Tape label
- ----------
- tape name = monthly_guest
- AFS tape name = guests.monthly.3
- creationTime = Mon Feb 1 04:06:40 1999
- cell = abc.com
- size = 2150000 Kbytes
- dump path = /monthly
- dump id = 917860000
- useCount = 44
- -- End of tape label --
-</PRE>
-<HR><H2><A NAME="HDRWQ374" HREF="auagd002.htm#ToC_309">Automating and Increasing the Efficiency of the Backup Process</A></H2>
-<A NAME="IDX6951"></A>
-<A NAME="IDX6952"></A>
-<P>The Backup System includes several optional features to help you automate
-the backup process in your cell and make it more efficient. By
-combining several of the features, you can dump volume data to tape with
-minimal human intervention in most cases. To take advantage of many of
-the features, you create a <I>device configuration file</I> in the
-<B>/usr/afs/backup</B> directory for each tape device that participates in
-automated operations. For general instructions on creating the device
-configuration file, see <A HREF="#HDRWQ375">Creating a Device Configuration File</A>. The following list refers you to sections that
-describe each feature in greater detail.
-<UL>
-<P><LI>You can use tape stackers and jukeboxes to perform backup
-operations. These are tape drives with an attached unit that stores
-several tapes and can physically insert and remove them from the tape reader
-(tape drive) without human intervention, meaning that no operator has to be
-present even for backup operations that require several tapes. To use a
-stacker or jukebox with the Backup System, include the <B>MOUNT</B> and
-<B>UNMOUNT</B> instructions in its device configuration file. See <A HREF="#HDRWQ376">Invoking a Device's Tape Mounting and Unmounting Routines</A>.
-<P><LI>You can suppress the Tape Coordinator's default prompt for the
-initial tape that it needs for a backup operation, again eliminating the need
-for a human operator to be present when a backup operation begins. (You
-must still insert the correct tape in the drive at some point before the
-operation begins.) To suppress the initial prompt, include the
-<B>-noautoquery</B> flag on the <B>butc</B> command, or assign the
-value <B>NO</B> to the <B>AUTOQUERY</B> instruction in the device
-configuration file. See <A HREF="#HDRWQ377">Eliminating the Search or Prompt for the Initial Tape</A>.
-<P><LI>You can suppress the prompts that the Tape Coordinator otherwise generates
-when it encounters several types of errors. When you use this feature,
-the Tape Coordinator instead responds to the errors in a default manner, which
-generally allows the operation to continue without human intervention.
-To suppress prompts about error conditions, assign the value <B>NO</B> to
-the <B>ASK</B> instruction in the device configuration file. See <A HREF="#HDRWQ378">Enabling Default Responses to Error Conditions</A>.
-<P><LI>You can suppress the Backup System's default verification that the
-AFS tape name on a tape that has no permanent name matches the name derived
-from the volume set and dump level names of the initial dump the Backup System
-is writing to the tape. This enables you to recycle a tape without
-first relabeling it, as long as all dumps on it are expired. To
-suppress name checking, assign the value <B>NO</B> to the
-<B>NAME_CHECK</B> instruction in the device configuration file. See
-<A HREF="#HDRWQ379">Eliminating the AFS Tape Name Check</A>.
-<P><LI>You can promote tape streaming (the most efficient way for a tape device
-to operate) by setting the size of the memory buffer the Tape Coordinator uses
-when transferring volume data between the file system and the device.
-To set the buffer size, include the <B>BUFFERSIZE</B> instruction in the
-device configuration file. See <A HREF="#HDRWQ380">Setting the Memory Buffer Size to Promote Tape Streaming</A>.
-<P><LI>You can write dumps to a <I>backup data file</I> on the local disk of
-the Tape Coordinator machine, rather than to tape. You can then
-transfer the backup data file to a data-archiving system, such as a
-hierarchical storage management (HSM) system, that you use in conjunction with
-AFS and the Backup System. Writing a dump to a file is usually more
-efficient that issuing the equivalent <B>vos dump</B> commands
-individually. To write dumps to a file, include the <B>FILE</B>
-instruction in the device configuration file. See <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A>.
-</UL>
-<P>There are two additional ways to increase backup automation and efficiency
-that do not involve the device configuration file:
-<UL>
-<P><LI>You can schedule one or more <B>backup dump</B> commands to run at
-specified times. This enables you to create backups at times of low
-system usage, without requiring a human operator to be present. You can
-schedule a single dump operation for a future time, or multiple operations to
-run at various future times. See <A HREF="auagd012.htm#HDRWQ415">Scheduling Dumps</A>.
-<P><LI>You can append dumps to a tape that already has other dumps on it.
-This enables you to use as much of a tape's capacity as possible.
-The appended dumps do not have be related in any way to one another or to the
-initial dump on the tape, but grouping dumps appropriately can reduce the
-number of necessary tape changes during a restore operation. To append
-a dump, include the <B>-append</B> argument to the <B>backup dump</B>
-command. See <A HREF="auagd012.htm#HDRWQ414">Appending Dumps to an Existing Dump Set</A>.
-</UL>
-<P><H3><A NAME="HDRWQ375" HREF="auagd002.htm#ToC_310">Creating a Device Configuration File</A></H3>
-<A NAME="IDX6953"></A>
-<A NAME="IDX6954"></A>
-<A NAME="IDX6955"></A>
-<A NAME="IDX6956"></A>
-<P>To use many of the features that automate backup operations, create a
-configuration file for each tape device in the <B>/usr/afs/backup</B>
-directory on the local disk of the Tape Coordinator machine that drives the
-device. The filename has the following form:
-<P><B>CFG_</B><VAR>device_name</VAR>
-<P>where <VAR>device_name</VAR> represents the name of the tape device or backup
-data file (see <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A> to learn about writing dumps to a file rather than to
-tape).
-<P>For a tape device, construct the <VAR>device_name</VAR> portion of the name
-by stripping off the initial <B>/dev/</B> string with which all UNIX
-device names conventionally begin, and replacing any other slashes in the name
-with underscores. For example, <B>CFG_rmt_4m</B> is the appropriate
-filename for a device called <B>/dev/rmt/4m</B>.
-<P>For a backup data file, construct the <VAR>device_name</VAR> portion by
-stripping off the initial slash (<B>/</B>) and replacing any other slashes
-(<B>/</B>) in the name with underscores. For example,
-<B>CFG_var_tmp_FILE</B> is the appropriate filename for a backup data file
-called <B>/var/tmp/FILE</B>.
-<P>Creating a device configuration file is optional. If you do not want
-to take advantage of any of the features that the file provides, you do not
-have to create it.
-<P>You can include one of each of the following instructions in any order in a
-device configuration file. All are optional. Place each
-instruction on its own line, but do not include any newline
-(<B><Return></B>) characters within an instruction.
-<DL>
-<P><DT><B>MOUNT and UNMOUNT
-</B><DD>Identify a script of routines for mounting and unmounting tapes in a tape
-stacker or jukebox's drive as needed. See <A HREF="#HDRWQ376">Invoking a Device's Tape Mounting and Unmounting Routines</A>.
-<P><DT><B>AUTOQUERY
-</B><DD>Controls whether the Tape Coordinator prompts for the first tape it needs
-for a backup operation. See <A HREF="#HDRWQ377">Eliminating the Search or Prompt for the Initial Tape</A>.
-<P><DT><B>ASK
-</B><DD>Controls whether the Tape Coordinator asks you how to respond to certain
-error conditions. See <A HREF="#HDRWQ378">Enabling Default Responses to Error Conditions</A>.
-<P><DT><B>NAME_CHECK
-</B><DD>Controls whether the Tape Coordinator verifies that an AFS tape name
-matches the initial dump you are writing to the tape. See <A HREF="#HDRWQ379">Eliminating the AFS Tape Name Check</A>.
-<P><DT><B>BUFFERSIZE
-</B><DD>Sets the size of the memory buffer the Tape Coordinator uses when
-transferring data between a tape device and a volume. See <A HREF="#HDRWQ380">Setting the Memory Buffer Size to Promote Tape Streaming</A>.
-<P><DT><B>FILE
-</B><DD>Controls whether the Tape Coordinator writes dumps to, and restores data
-from, a tape device or a backup data file. See <A HREF="#HDRWQ381">Dumping Data to a Backup Data File</A>.
-</DL>
-<A NAME="IDX6957"></A>
-<A NAME="IDX6958"></A>
-<A NAME="IDX6959"></A>
-<A NAME="IDX6960"></A>
-<A NAME="IDX6961"></A>
-<A NAME="IDX6962"></A>
-<P><H3><A NAME="HDRWQ376" HREF="auagd002.htm#ToC_311">Invoking a Device's Tape Mounting and Unmounting Routines</A></H3>
-<P>A tape stacker or jukebox helps you automate backup
-operations because it can switch between multiple tapes during an operation
-without human intervention. To take advantage of this feature, include
-the <B>MOUNT</B> and optionally <B>UNMOUNT</B> instructions in the
-device configuration file that you write for the stacker or jukebox.
-The instructions share the same syntax:
-<PRE> <B>MOUNT</B> <VAR>filename</VAR>
- <B>UNMOUNT</B> <VAR>filename</VAR>
-</PRE>
-<P>where <VAR>filename</VAR> is the pathname on the local disk of a script or
-program you have written that invokes the routines defined by the
-device's manufacturer for mounting or unmounting a tape in the
-device's tape drive. (For convenience, the following discussion
-uses the term <I>script</I> to refers to both scripts and
-programs.) The script usually also contains additional logic that
-handles error conditions or modifies the script's behavior depending on
-which backup operation is being performed.
-<P>You can refer to different scripts with the <B>MOUNT</B> or
-<B>UNMOUNT</B> instructions, or to a single script that invokes both
-mounting and unmounting routines. The scripts inherit the local
-identity and AFS tokens associated with to the issuer of the <B>butc</B>
-command.
-<P>You need to include a <B>MOUNT</B> instruction in the device
-configuration file for all tape devices, but the need for an
-<B>UNMOUNT</B> instruction depends on the tape-handling routines that the
-device's manufacturer provides. Some devices, usually stackers,
-have only a single routine for mounting tapes, which also automatically
-unmounts a tape whose presence prevents insertion of the required new
-tape. In this case, an <B>UNMOUNT</B> instruction is not
-necessary. For devices that have separate mounting and unmounting
-routines, you must include an <B>UNMOUNT</B> instruction to remove a tape
-when the Tape Coordinator is finished with it; otherwise, subsequent
-attempts to run the <B>MOUNT</B> instruction fail with an error.
-<P>When the device configuration file includes a <B>MOUNT</B> instruction,
-you must stock the stacker or jukebox with the necessary tapes before running
-a backup operation. Many jukeboxes are able to search for the required
-tape by reading external labels (such as barcodes) on the tapes, but many
-stackers can only switch between tapes in sequence and sometimes only in one
-direction. In the latter case, you must also stock the tapes in the
-correct order.
-<P>To obtain a list of the tapes required for a restore operation so that you
-can prestock them in the tape device, include the <B>-n</B> flag on the
-appropriate <B>backup</B> command (<B>backup diskrestore</B>,
-<B>backup volrestore</B>, or <B>backup volsetrestore</B>). For
-a dump operation, it is generally sufficient to stock the device with more
-tapes than the operation is likely to require. You can prelabel the
-tapes with permanent names or AFS tape names, or not prelabel them at
-all. If you prelabel the tapes for a dump operation with AFS tape
-names, then it is simplest to load them into the stacker in sequential order
-by tape index. But it is probably simpler still to prelabel tapes with
-permanent tape names or use unlabeled tapes, in which case the Backup System
-generates and applies the appropriately indexed AFS tape name itself during
-the dump operation.
-<P><H4><A NAME="Header_312">How the Tape Coordinator Uses the MOUNT and UNMOUNT Instructions</A></H4>
-<P>When you issue the <B>butc</B> command to initialize the Tape
-Coordinator for a given tape device, the Tape Coordinator looks for the device
-configuration file called <B>/usr/afs/backup/CFG_</B><VAR>device_name</VAR>
-on its local disk, where <VAR>device_name</VAR> has the format described in <A HREF="#HDRWQ375">Creating a Device Configuration File</A>. If the file exists and contains a <B>MOUNT</B>
-instruction, then whenever the Tape Coordinator needs a tape, it executes the
-script named by the instruction's <VAR>filename</VAR> argument.
-<P>If the device configuration file does not exist, or does not include a
-<B>MOUNT</B> instruction, then whenever the Tape Coordinator needs a tape,
-it generates a prompt in its window instructing the operator to insert the
-necessary tape. The operator must insert the tape and press
-<B><Return></B> before the Tape Coordinator continues the backup
-operation.
-<P>Note, however, that you can modify the Tape Coordinator's behavior
-with respect to the first tape needed for an operation, by setting the
-<B>AUTOQUERY</B> instruction in the device configuration file to
-<B>NO</B>, or including the <B>-noautoquery</B> flag to the
-<B>butc</B> command. In this case, the Tape Coordinator does not
-execute the <B>MOUNT</B> instruction or prompt for a tape at the start of
-an operation, because it expects to find the required first tape in the
-drive. See <A HREF="#HDRWQ377">Eliminating the Search or Prompt for the Initial Tape</A>.
-<P>If there is an <B>UNMOUNT</B> instruction in the device configuration
-file, then whenever the Tape Coordinator closes the tape device, it executes
-the script named by the instruction's <VAR>filename</VAR> argument.
-It executes the script only once, and regardless of whether the
-<B>close</B> operation on the device succeeded or not. If the
-device configuration file does not include an <B>UNMOUNT</B> instruction,
-then the Tape Coordinator takes no action.
-<P><H4><A NAME="Header_313">The Available Parameters and Required Exit Codes</A></H4>
-<P>When the Tape Coordinator executes the <B>MOUNT</B> script, it
-passes in five parameters, ordered as follows. You can use the
-parameters in your script to refine its response to varying circumstances that
-can arise during a backup operation.
-<OL TYPE=1>
-<P><LI>The tape device or backup data file's pathname, as recorded in the
-<B>/usr/afs/backup/tapeconfig</B> file.
-<P><LI>The tape operation, which (except for the exceptions noted in the
-following list) matches the <B>backup</B> command operation code used to
-initiate the operation:
-<UL>
-<P><LI><B>appenddump</B> (when a <B>backup dump</B> command includes the
-<B>-append</B> flag)
-<P><LI><B>dump</B> (when a <B>backup dump</B> command does not include
-the <B>-append</B> flag)
-<P><LI><B>labeltape</B>
-<P><LI><B>readlabel</B>
-<P><LI><B>restore</B> (for a <B>backup diskrestore</B>, <B>backup
-volrestore</B>, or <B>backup volsetrestore</B> command)
-<P><LI><B>restoredb</B>
-<P><LI><B>savedb</B>
-<P><LI><B>scantape</B>
-</UL>
-<P><LI>The number of times the Tape Coordinator has attempted to open the tape
-device or backup data file. If the open attempt returns an error, the
-Tape Coordinator increments this value by one and again invokes the
-<B>MOUNT</B> instruction.
-<P><LI>The tape name. For some operations, the Tape Coordinator passes the
-string <TT>none</TT>, because it does not know the tape name (when running
-the <B>backup scantape</B> or <B>backup readlabel</B>, for example),
-or because the tape does not necessarily have a name (when running the
-<B>backup labeltape</B> command, for example).
-<P><LI>The tape ID recorded in the Backup Database. As with the tape name,
-the Backup System passes the string <TT>none</TT> for operations where it
-does not know the tape ID or the tape does not necessarily have an ID.
-</OL>
-<P>Your <B>MOUNT</B> script must return one of the following exit codes to
-tell the Tape Coordinator whether or not it mounted the tape
-successfully:
-<UL>
-<P><LI>Code <B>0</B> (zero) indicates a successful mount, and the Tape
-Coordinator continues the backup operation. If the script or program
-called by the <B>MOUNT</B> instruction does not return this exit code, the
-Tape Coordinator never calls the <B>UNMOUNT</B> instruction.
-<P><LI>Code <B>1</B> indicates that mount attempt failed. The Tape
-Coordinator terminates the backup operation.
-<P><LI>Any other code indicates that the script was unable to access the correct
-tape. The Tape Coordinator prompts the operator to insert it.
-</UL>
-<P>When the Tape Coordinator executes the <B>UNMOUNT</B> script, it passes
-in two parameters in the following order.
-<OL TYPE=1>
-<P><LI>The tape device's pathname (as specified in the
-<B>/usr/afs/backup/tapeconfig</B> file)
-<P><LI>The tape operation, which is always <B>unmount</B>.
-</OL>
-<P>The following example script uses two of the parameters passed to it by the
-Backup System: <TT>tries</TT> and <TT>operation</TT>. It
-follows the recommended practice of exiting if the value of the
-<TT>tries</TT> parameter exceeds one, because that implies that the stacker
-is out of tapes.
-<P>For a <B>backup dump</B> or <B>backup savedb</B> operation, the
-routine calls the example <B>stackerCmd_NextTape</B> function provided by
-the stacker's manufacturer. Note that the final lines in the file
-return the exit code that prompts the operator to insert a tape; these
-lines are invoked when either the stacker cannot load a tape or a the
-operation being performed is not one of those explicitly mentioned in the file
-(is a restore operation, for example).
-<PRE> #! /bin/csh -f
-
- set devicefile = $1
- set operation = $2
- set tries = $3
- set tapename = $4
- set tapeid = $5
- set exit_continue = 0
- set exit_abort = 1
- set exit_interactive = 2
- #--------------------------------------------
- if (${tries} > 1) then
- echo "Too many tries"
- exit ${exit_interactive}
- endif
- if (${operation} == "unmount") then
- echo "UnMount: Will leave tape in drive"
- exit ${exit_continue}
- endif
- if ((${operation} == "dump") |\
- (${operation} == "appenddump") |\
- (${operation} == "savedb")) then
-
- stackerCmd_NextTape ${devicefile}
- if (${status} != 0)exit${exit_interactive}
- echo "Will continue"
- exit ${exit_continue}
- endif
-
- if ((${operation} == "labeltape") |\
- (${operation} == "readlabel")) then
- echo "Will continue"
- exit ${exit_continue}
- endif
-
- echo "Prompt for tape"
- exit ${exit_interactive}
-</PRE>
-<A NAME="IDX6963"></A>
-<A NAME="IDX6964"></A>
-<A NAME="IDX6965"></A>
-<A NAME="IDX6966"></A>
-<P><H3><A NAME="HDRWQ377" HREF="auagd002.htm#ToC_314">Eliminating the Search or Prompt for the Initial Tape</A></H3>
-<P>By default, the Tape Coordinator obtains the first tape it
-needs for a backup operation by reading the device configuration file for the
-appropriate tape device. If there is a <B>MOUNT</B> instruction in
-the file, the Tape Coordinator executes the referenced script. If the
-device configuration file does not exist or does not have a <B>MOUNT</B>
-instruction in it, the Tape Coordinator prompts you to insert the correct tape
-and press <B><Return></B>.
-<P>If you know in advance that an operation requires a tape, you can increase
-efficiency by placing the required tape in the drive before issuing the
-<B>backup</B> command and telling the Tape Coordinator's to skip its
-initial tape-acquisition steps. This both enables the operation to
-begin more quickly and eliminates that need for you to be present to insert a
-tape.
-<P>There are two ways to bypass the Tape Coordinator's initial
-tape-acquisition steps:
-<OL TYPE=1>
-<P><LI>Include the instruction <B>AUTOQUERY NO</B> in the device
-configuration file
-<P><LI>Include the <B>-noautoquery</B> flag to the <B>butc</B> command
-</OL>
-<P>To avoid any error conditions that require operator attention, be sure that
-the tape you are placing in the drive does not contain any unexpired dumps and
-is not write protected. If there is no permanent name on the
-tape's label and you are creating an initial dump, make sure that the AFS
-tape name either matches the volume set and dump set names or is
-<TT><NULL></TT>. Alternatively, suppress the Tape
-Coordinator's name verification step by assigning the value <B>NO</B>
-to the <B>NAME_CHECK</B> instruction in the device configuration file, as
-described in <A HREF="#HDRWQ379">Eliminating the AFS Tape Name Check</A>.
-<A NAME="IDX6967"></A>
-<A NAME="IDX6968"></A>
-<A NAME="IDX6969"></A>
-<P><H3><A NAME="HDRWQ378" HREF="auagd002.htm#ToC_315">Enabling Default Responses to Error Conditions</A></H3>
-<P>By default, the Tape Coordinator asks you how to respond
-when it encounters certain error conditions. To suppress the prompts
-and cause the Tape Coordinator to handle the errors in a predetermined manner,
-include the instruction <B>ASK NO</B> in the device configuration
-file. If you assign the value <B>YES</B>, or omit the
-<B>ASK</B> instruction completely, the Tape Coordinator prompts you for
-direction when it encounters one of the errors.
-<P>The following list describes the error conditions and the Tape
-Coordinator's response to them.
-<UL>
-<P><LI>The Backup System is unable to dump a volume while running the <B>backup
-dump</B> command. When you assign the value <B>NO</B>, the Tape
-Coordinator omits the volume from the dump and continues the operation.
-When you assign the value <B>YES</B>, it prompts to ask if you want to try
-to dump the volume again immediately, to omit the volume from the dump but
-continue the operation, or to terminate the operation.
-<P><LI>The Backup System is unable to restore a volume while running the
-<B>backup diskrestore</B>, <B>backup volrestore</B>, or <B>backup
-volsetrestore</B> command. When you assign the value <B>NO</B>,
-the Tape Coordinator continues the operation, omitting the problematic volume
-but restoring the remaining ones. When you assign the value
-<B>YES</B>, it prompts to ask if you want to omit the volume and continue
-the operation, or to terminate the operation.
-<P><LI>The Backup System cannot determine if the dump set includes any more tapes
-while running the <B>backup scantape</B> command (the command's
-reference page in the <I>AFS Administration Reference</I> discusses
-possible reasons for this problem). When you assign the value
-<B>NO</B>, the Tape Coordinator proceeds as though there are more tapes
-and invokes the <B>MOUNT</B> script named in the device configuration
-file, or prompts the operator to insert the next tape. When you assign
-the value <B>YES</B>, it prompts to ask if there are more tapes to
-scan.
-<P><LI>The Backup System determines that the tape contains an unexpired dump
-while running the <B>backup labeltape</B> command. When you assign
-the value <B>NO</B>, it terminates the operation without relabeling the
-tape. With a <B>YES</B> value, the Tape Coordinator prompts to ask
-if you want to relabel the tape anyway.
-</UL>
-<A NAME="IDX6970"></A>
-<A NAME="IDX6971"></A>
-<A NAME="IDX6972"></A>
-<A NAME="IDX6973"></A>
-<P><H3><A NAME="HDRWQ379" HREF="auagd002.htm#ToC_316">Eliminating the AFS Tape Name Check</A></H3>
-<P>If a tape does not have a permanent name and you are writing
-an initial dump to it, then by default the Backup System verifies that the
-tape's AFS tape name is acceptable. It accepts three types of
-values:
-<UL>
-<P><LI>A name that reflects the volume set and dump level of the initial dump and
-the tape's place in the sequence of tapes for the dump set, as described
-in <A HREF="#HDRWQ352">Dump Names and Tape Names</A>. If the tape does not already have a permanent name,
-you can assign the AFS tape name by using the <B>-name</B> argument to the
-<B>backup labeltape</B> command.
-<P><LI>A <TT><NULL></TT> value, which results when you assign a permanent
-name, or provide no value for the <B>backup labeltape</B> command's
-<B>-name</B> argument.
-<P><LI>No AFS tape name at all, indicating that you have never labeled the tape
-or written a dump to it.
-</UL>
-<P>To bypass the name check, include the <B>NAME_CHECK NO</B> instruction
-in the device configuration file. This enables you to recycle a tape
-without first relabeling it, as long as all dumps on it are expired.
-(If a tape has unexpired dumps on it but you want to recycle it anyway, you
-must use the <B>backup labeltape</B> command to relabel it first.
-For this to work, the <B>ASK NO</B> instruction cannot appear in the
-device configuration file.)
-<P><H3><A NAME="HDRWQ380" HREF="auagd002.htm#ToC_317">Setting the Memory Buffer Size to Promote Tape Streaming</A></H3>
-<P>By default, the Tape Coordinator uses a 16-KB memory buffer
-during dump operations. As it receives volume data from the Volume
-Server, the Tape Coordinator gathers 16 KB of data in the buffer before
-transferring the entire 16 KB to the tape device. Similarly, during a
-restore operation the Tape Coordinator by default buffers 32 KB of data from
-the tape device before transferring the entire 32 KB to the Volume Server for
-restoration into the file system. Buffering makes the volume of data
-flowing to and from a tape device more even and so promotes tape streaming,
-which is the most efficient way for a tape device to operate.
-<P>In a normal network configuration, the default buffer sizes are usually
-large enough to promote tape streaming. If the network between the Tape
-Coordinator machine and file server machines is slow, it can help to increase
-the buffer size.
-<P>To determine if altering the buffer size is helpful for your configuration,
-observe the tape device in operation to see if it is streaming, or consult the
-manufacturer. To set the buffer size, include the <B>BUFFERSIZE</B>
-instruction in the device configuration file. It takes an integer
-value, and optionally units, in the following format:
-<PRE> <B>BUFFERSIZE</B> <VAR>size</VAR>[{<B>k</B> | <B>K</B> | <B>m</B> | <B>M</B> | <B>g</B> | <B>G</B>}]
-</PRE>
-<P>where <VAR>size</VAR> specifies the amount of memory the Tape Coordinator
-allocates to use as a buffer during both dump and restore operations.
-The default unit is bytes, but use <B>k</B> or <B>K</B> to specify
-kilobytes, <B>m</B> or <B>M</B> for megabytes, and <B>g</B> or
-<B>G</B> for gigabytes. There is no space between the <VAR>size</VAR>
-value and the units letter.
-<P><H3><A NAME="HDRWQ381" HREF="auagd002.htm#ToC_318">Dumping Data to a Backup Data File</A></H3>
-<P>You can write dumps to a <I>backup data file</I> rather
-than to tape. This is useful if, for example, you want to transfer the
-data to a data-archiving system, such as a hierarchical storage management
-(HSM) system, that you use in conjunction with AFS and the Backup
-System. You can restore data from a backup data file into the file
-system as well. Using a backup data file is usually more efficient than
-issuing the equivalent <B>vos dump</B> and <B>vos restore</B> commands
-individually for multiple volumes.
-<P>Writing to a backup data file is simplest if it is on the local disk of the
-Tape Coordinator machine, but you can also write the file to an NFS-mounted
-partition that resides on a remote machine. It is even acceptable to
-write to a file in AFS, provided that the access control list (ACL) on its
-parent directory grants the necessary permissions, but it is somewhat circular
-to back up AFS data into AFS itself.
-<P>If the backup data file does not already exist when the Tape Coordinator
-attempts to write a dump to it, the Tape Coordinator creates it. For a
-restore operation to succeed, the file must exist and contain volume data
-previously written to it during a <B>backup dump</B> operation.
-<P>When writing to a backup data file, the Tape Coordinator writes data at 16
-KB offsets. If a given block of data (such as the marker that signals
-the beginning or end of a volume) does not fill the entire 16 KB, the Tape
-Coordinator still skips to the next offset before writing the next
-block. In the output of a <B>backup dumpinfo</B> command issued
-with the <B>-id</B> option, the value in the <TT>Pos</TT> column is the
-ordinal of the 16-KB offset at which the volume data begins, and so is not
-generally only one higher than the position number on the previous line, as it
-is for dumps to tape.
-<P>Before writing to a backup data file, you need to configure the file as
-though it were a tape device.
-<TABLE><TR><TD ALIGN="LEFT" VALIGN="TOP"><B>Note:</B></TD><TD ALIGN="LEFT" VALIGN="TOP">A file pathname, rather than a tape device name, must appear in the third
-field of the <B>/usr/afs/backup/tapeconfig</B> file when the <B>FILE
-YES</B> instruction appears in the device configuration file, and vice
-versa. If the <B>tapeconfig</B> file instead refers to a tape
-device, dump operations appear to succeed but are inoperative. You
-cannot restore data that you accidently dumped to a tape device while the
-<B>FILE</B> instruction was set to <B>YES</B>. In the same way,
-if the <B>FILE</B> instruction is set to <B>NO</B>, the
-<B>tapeconfig</B> entry must refer to an actual tape device.
-</TD></TR></TABLE>
-<P><H3><A NAME="Header_319" HREF="auagd002.htm#ToC_319">To configure a backup data file</A></H3>
-<OL TYPE=1>
-<P><LI>Verify that you are authenticated as a user listed in the
-<B>/usr/afs/etc/UserList</B> file. If necessary, issue the <B>bos
-listusers</B> command, which is fully described in <A HREF="auagd021.htm#HDRWQ815">To display the users in the UserList file</A>.
-<PRE> % <B>bos listusers</B> <<VAR>machine name</VAR>>
-</PRE>
-<P><LI>Become the local superuser <B>root</B> on the machine, if you are not
-already, by issuing the <B>su</B> command.
-<PRE> % <B>su root</B>
- Password: <VAR>root_password</VAR>
-</PRE>
-<P><LI><B>Optional</B>. Issue the <B>backup</B> command to enter
-interactive mode.
-<PRE> # <B>backup</B>
-</PRE>
-<P><LI>Choose the port offset number to assign to the file. If necessary,
-display previously assigned port offsets by issuing the <B>(backup)
-listhosts</B> command, which is fully described in <A HREF="#HDRWQ363">To display the list of configured Tape Coordinators</A>.
-<PRE> backup> <B>listhosts</B>
-</PRE>
-<P>As for a tape device, acceptable values are the integers <B>0</B>
-(zero) through <B>58510</B> (the Backup System can track a maximum of
-58,511 port offset numbers). Each port offset must be unique in the
-cell, but you can associate any number them with a single Tape Coordinator
-machine. You do not have to assign port offset numbers
-sequentially.
-<P><LI>Issue the <B>(backup) addhost</B> command to register the backup data
-file's port offset in the Backup Database.
-<PRE> backup> <B>addhost</B> <<VAR>tape machine name</VAR>> [<<VAR>TC port offset</VAR>>]
-</PRE>
-<P>where
-<DL>
-<P><DT><B>addh
-</B><DD>Is the shortest acceptable abbreviation of <B>addhost</B>.
-<P><DT><B><VAR>tape machine name</VAR>
-</B><DD>Specifies the fully qualified hostname of the Tape Coordinator machine you
-invoke to write to the backup data file.
-<P><DT><B><VAR>TC port offset</VAR>
-</B><DD>Specifies the file's port offset number. You must provide this
-argument unless the default value of <B>0</B> (zero) is
-appropriate.
-</DL>
-<P><LI><A NAME="LITAPECONFIG-FILE"></A>Using a text editor, create an entry for the backup
-data file in the local <B>/usr/afs/backup/tapeconfig</B> file, using the
-standard syntax:
-<PRE> [<VAR>capacity</VAR> <VAR>filemark_size</VAR>] <VAR>device_name</VAR> <VAR>port_offset</VAR>
-</PRE>
-<P>where
-<DL>
-<P><DT><B><VAR>capacity</VAR>
-</B><DD>Specifies the amount of space on the partition that houses the backup data
-file that you want to make available for the file. To avoid the
-complications that arise from filling up the partition, it is best to provide
-a value somewhat smaller than the actual amount of space you expect to be
-available when the dump operation runs, and never larger than the maximum file
-size allowed by the operating system.
-<P>Specify a numerical value followed by a letter that indicates units, with
-no intervening space. The letter <B>k</B> or <B>K</B> indicates
-kilobytes, <B>m</B> or <B>M</B> indicates megabytes, and <B>g</B>
-or <B>G</B> indicates gigabytes. If you omit the units letter, the
-default is kilobytes. If you leave this field empty, the Tape
-Coordinator uses the maximum acceptable value (2048 GB or 2 TB). Also
-leave the <VAR>filemark_size</VAR> field empty in that case.
-<P><DT><B><VAR>filemark_size</VAR>
-</B><DD>Specify the value <B>0</B> (zero) or leave both this field and the
-<VAR>capacity</VAR> field empty. In the latter case, the Tape Coordinator
-also uses the value zero.
-<P><DT><B><VAR>device_name</VAR>
-</B><DD>Specifies the complete pathname of the backup data file. Rather
-than specifying an actual file pathname, however, the recommended
-configuration is to create a symbolic link in the <B>/dev</B> directory
-that points to the actual file pathname, and record the symbolic link in this
-field. This configuration provides these advantages:
-<UL>
-<P><LI>It makes the <VAR>device_name</VAR> portion of the
-<B>CFG_</B><VAR>device_name</VAR>, of the
-<B>TE_</B><VAR>device_name</VAR>, and of the
-<B>TL_</B><VAR>device_name</VAR> filenames as short as possible.
-Because the symbolic link is in the <B>/dev</B> directory as though it is
-a tape device, you strip off the entire <B>/dev/</B> prefix when forming
-the filename, instead of just the initial slash (<B>/</B>). If, for
-example, the symbolic link is called <B>/dev/FILE</B>, the device
-configuration file's name is <B>CFG_FILE</B>, whereas if the actual
-pathname /<B>var/tmp/FILE</B> appears in the <B>tapeconfig</B> file,
-the configuration file's name must be <B>CFG_var_tmp_FILE</B>.
-<P><LI>It provides for a more graceful, and potentially automated, recovery if
-the Tape Coordinator cannot write a complete dump into the backup data file
-(for example, because the partition housing the backup data file becomes
-full). The Tape Coordinator's reaction to this problem is to
-invoke the <B>MOUNT</B> script, or to prompt you if the <B>MOUNT</B>
-instruction does not appear in the configuration file.
-<UL>
-<P><LI>If there is a <B>MOUNT</B> script, you can prepare for this situation
-by adding a subroutine to the script that changes the symbolic link to point
-to another backup data file on a partition where there is space
-available.
-<P><LI>If there is no <B>MOUNT</B> instruction, the prompt enables you
-manually to change the symbolic link to point to another backup data file and
-then press <<B>Return</B>> to signal that the Tape Coordinator can
-continue the operation.
-</UL>
-<P>If this field names the actual file, there is no way to recover from
-exhausting the space on the partition. You cannot change the
-<B>tapeconfig</B> file in the middle of an operation.
-</UL>
-<P><DT><B><VAR>port_offset</VAR>
-</B><DD>Specifies the port offset number that you chose for the backup data
-file.
-</DL>
-<P><LI>Create the device configuration file <B>CFG_</B><VAR>device_name</VAR>
-in the Tape Coordinator machine's <B>/usr/afs/backup</B>
-directory. Include the <B>FILE YES</B> instruction in the
-file.
-<P>Construct the <VAR>device_name</VAR> portion of the name based on the device
-name you recorded in the <B>tapeconfig</B> file in Step <A HREF="#LITAPECONFIG-FILE">6</A>. If, as recommended, you recorded a symbolic link
-name, strip off the <B>/dev/</B> string and replace any other slashes
-(<B>/</B>) in the name with underscores (<B>_</B>). For
-example, <B>CFG_FILE</B> is the appropriate name if the symbolic link is
-<B>/dev/FILE</B>. If you recorded the name of an actual file, then
-strip off the initial slash only and replace any other slashes in the name
-with underscores. For a backup data file called
-<B>/var/tmp/FILE</B>, the appropriate device configuration filename is
-<B>CFG_var_tmp_FILE</B>.
-<P><LI>If you chose in Step <A HREF="#LITAPECONFIG-FILE">6</A> to record a symbolic link name in the <VAR>device_name</VAR>
-field of the <B>tapeconfig</B> entry, then you must do one of the
-following:
-<UL>
-<P><LI>Use the <B>ln -s</B> command to create the appropriate symbolic link
-in the <B>/dev</B> directory
-<P><LI>Write a script that initializes the backup data file in this way, and
-include a <B>MOUNT</B> instruction in the device configuration file to
-invoke the script. An example script appears following these
-instructions.
-</UL>
-</OL>
-<P>You do not need to create the backup data file itself, because the Tape
-Coordinator does so if the file does not exist when the dump operation
-begins.
-<P>The following example script illustrates how you can automatically create a
-symbolic link to the backup data file during the preparation phase for writing
-to the file. When the Tape Coordinator is executing a <B>backup
-dump</B>, <B>backup restore</B>, <B>backup savedb</B>, or
-<B>backup restoredb</B> operation, the routine invokes the UNIX <B>ln
--s</B> command to create a symbolic link from the backup data file named in
-the <B>tapeconfig</B> file to the actual file to use (this is the
-recommended method). It uses the values of the <TT>tapename</TT> and
-<TT>tapeid</TT> parameters passed to it by the Backup System when
-constructing the filename.
-<P>The routine makes use of two other parameters as well:
-<TT>tries</TT> and <TT>operation</TT>. The <TT>tries</TT>
-parameter tracks how many times the Tape Coordinator has attempted to access
-the file. A value greater than one indicates that the Tape Coordinator
-cannot access it, and the routine returns exit code 2
-(<TT>exit_interactive</TT>), which results in a prompt for the operator to
-load a tape. The operator can use this opportunity to change the name
-of the backup data file specified in the <B>tapeconfig</B> file.
-<PRE> #! /bin/csh -f
- set devicefile = $1
- set operation = $2
- set tries = $3
- set tapename = $4
- set tapeid = $5
- set exit_continue = 0
- set exit_abort = 1
- set exit_interactive = 2
- #--------------------------------------------
- if (${tries} > 1) then
- echo "Too many tries"
- exit ${exit_interactive}
- endif
- if (${operation} == "labeltape") then
- echo "Won't label a tape/file"
- exit ${exit_abort}
- endif
- if ((${operation} == "dump") |\
- (${operation} == "appenddump") |\
- (${operation} == "restore") |\
- (${operation} == "savedb") |\
- (${operation} == "restoredb")) then
-
- /bin/rm -f ${devicefile}
- /bin/ln -s /hsm/${tapename}_${tapeid} ${devicefile}
- if (${status} != 0) exit ${exit_abort}
- endif
-
- exit ${exit_continue}
-</PRE>
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