3 afsd - Initializes the Cache Manager and starts related daemons
10 B<afsd> [B<-afsdb>] [B<-backuptree>]
11 S<<< [B<-biods> <I<number of bkg I/O daemons (aix vm)>>] >>>
12 S<<< [B<-blocks> <I<1024 byte blocks in cache>>] >>>
13 S<<< [B<-cachedir> <I<cache directory>>] >>>
14 S<<< [B<-chunksize> <I<log(2) of chunk size>>] >>>
15 S<<< [B<-confdir> <I<configuration directory>>] >>>
16 S<<< [B<-daemons> <I<number of daemons to use>>] >>>
17 S<<< [B<-dcache> <I<number of dcache entries>>] >>> [B<-debug>]
18 [B<-dynroot>] [B<-enable_peer_stats>] [B<-enable_process_stats>]
19 [B<-fakestat>] [B<-fakestat-all>]
20 S<<< [B<-files> <I<files in cache>>] >>>
21 S<<< [B<-files_per_subdir> <I<log(2) of files per dir>> ] >>>
22 [B<-help>] S<<< [B<-logfile> <I<Place to keep the CM log>>] >>>
23 [B<-mem_alloc_sleep>] [B<-memcache>]
24 S<<< [B<-mountdir> <I<mount location>>] >>> [B<-nomount>]
26 S<<< [B<-prealloc> <I<number of 'small' preallocated blocks>>] >>>
27 [B<-rmtsys>] S<<< [B<-rootvol> <I<name of AFS root volume>>] >>>
28 [B<-rxbind>] S<<< [B<-rxpck> value for rx_extraPackets ] >>>
29 [B<-settime>] [B<-shutdown>]
30 S<<< [B<-splitcache> <I<RW/RO ratio>>] >>>
31 S<<< [B<-stat> <I<number of stat entries>>] >>> [B<-verbose>]
32 S<<< [B<-volumes> <I<number of volume entries>>] >>>
40 The B<afsd> command initializes the Cache Manager on an AFS client machine
41 by transferring AFS-related configuration information into kernel memory
42 and starting several daemons. More specifically, the B<afsd> command
43 performs the following actions:
49 Sets a field in kernel memory that defines the machine's cell
50 membership. Some Cache Manager-internal operations and system calls
51 consult this field to learn which cell to execute in. (The AFS command
52 interpreters refer to the F</usr/vice/etc/ThisCell> file instead.) This
53 information is transferred into the kernel from the
54 F</usr/vice/etc/ThisCell> file and cannot be changed until the B<afsd>
59 Places in kernel memory the names and Internet addresses of the database
60 server machines in the local cell and (optionally) foreign cells. The
61 appearance of a cell's database server machines in this list enables the
62 Cache Manager to contact them and to access files in the cell. Omission of
63 a cell from this list, or incorrect information about its database server
64 machines, prevents the Cache Manager from accessing files in it.
66 By default, the list of database server machines is transferred into the
67 kernel from the F</usr/vice/etc/CellServDB> file. Alternatively, when the
68 B<-afsdb> option is used, the list of database server machines is taken
69 from the AFSDB DNS records for each cell. After initialization, use the
70 B<fs newcell> command to change the kernel-resident list without having to
75 Mounts the root of the AFS filespace on a directory on the machine's local
76 disk, according to either the first field in the
77 F</usr/vice/etc/cacheinfo> file (the default) or the B<afsd> command's
78 B<-mountdir> argument. The conventional value is F</afs>.
82 Determines which volume to mount at the root of the AFS file tree. The
83 default is the volume C<root.afs>; use the B<-rootvol> argument to
84 override it. Although the base (read/write) form of the volume name is the
85 appropriate value, the Cache Manager has a bias for accessing the
86 read-only version of the volume (by convention, C<root.afs.readonly>) if
91 Configures the cache on disk (the default) or in machine memory if the
92 B<-memcache> argument is provided. In the latter case, the B<afsd> program
93 allocates space in machine memory for caching, and the Cache Manager uses
94 no disk space for caching even if the machine has a disk.
98 Defines the name of the local disk directory devoted to caching, when the
99 B<-memcache> argument is not used. If necessary, the B<afsd> program
100 creates the directory (its parent directory must already exist). It does
101 not remove the directory that formerly served this function, if one
104 The second field in the F</usr/vice/etc/cacheinfo> file is the source for
105 this name. The standard value is F</usr/vice/cache>. Use the B<-cachedir>
106 argument to override the value in the B<cacheinfo> file.
110 Sets the size of the cache. The default source for the value is the third
111 field in the F</usr/vice/etc/cacheinfo> file, which specifies a number of
114 For a memory cache, the following arguments to the afsd command override
115 the value in the B<cacheinfo> file:
121 The B<-blocks> argument, to specify a different number of kilobyte blocks.
125 The B<-dcache> and B<-chunksize> arguments together, to set both the
126 number of dcache entries and the chunk size (see below for definition of
127 these parameters). In this case, the B<afsd> program derives cache size by
128 multiplying the two values. Using this combination is not recommended, as
129 it requires the issuer to perform the calculation beforehand to determine
130 the resulting cache size.
134 The B<-dcache> argument by itself. In this case, the B<afsd> program
135 derives cache size by multiplying the value specified by the B<-dcache>
136 argument by the default memory cache chunk size of eight kilobytes. Using
137 this argument is not recommended, as it requires the issuer to perform the
138 calculation beforehand to determine the resulting cache size.
142 For satisfactory memory cache performance, the specified value must leave
143 enough memory free to accommodate all other processes and commands that
144 can run on the machine. If the value exceeds the amount of memory
145 available, the B<afsd> program exits without initializing the Cache
146 Manager and produces the following message on the standard output stream:
148 afsd: memCache allocation failure at <number> KB
150 where <number> is how many kilobytes were allocated just before the
153 For a disk cache, use the B<-blocks> argument to the B<afsd> command to
154 override the value in the B<cacheinfo> file. The value specified in either
155 way sets an absolute upper limit on cache size; values provided for other
156 arguments (such as B<-dcache> and B<-chunksize>) never result in a larger
157 cache. The B<afsd> program rejects any setting larger than 95% of the
158 partition size, and exits after generating an error message on the
159 standard output stream, because the cache implementation itself requires a
160 small amount of disk space and overfilling the partition can cause the
161 client machine to panic.
163 To change the size of a disk cache after initialization without rebooting,
164 use the B<fs setcachesize> command; the setting persists until the B<afsd>
165 command runs again or the B<fs setcachesize> command is reissued. The B<fs
166 setcachesize> command does not work for memory caches.
170 Sets the size of each cache I<chunk>, and by implication the amount of
171 data that the Cache Manager requests at a time from the File Server (how
172 much data per fetch RPC, since AFS uses partial file transfer).
174 For a disk cache, a chunk is a F<VI<n>> file and this parameter
175 sets the maximum size to which each one can expand; the default is 64
176 KB. For a memory cache, each chunk is a collection of contiguous memory
177 blocks; the default is size is 8 KB.
179 To override the default chunk size for either type of cache, use the
180 B<-chunksize> argument to provide an integer to be used as an exponent of
181 two; see L<OPTIONS> for details. For a memory cache, if total cache size
182 divided by chunk size leaves a remainder, the B<afsd> program rounds down
183 the number of dcache entries, resulting in a slightly smaller cache.
187 Sets the number of chunks in the cache. For a memory cache, the number of
188 chunks is equal to the cache size divided by the chunk size. For a disk
189 cache, the number of chunks (F<VI<n>> files) is set to the largest
190 of the following unless the B<-files> argument is used to set the value
201 1.5 times the result of dividing cache size by chunk size
202 (I<cachesize>/I<chunksize> * 1.5)
206 The result of dividing cachesize by 10 KB (I<cachesize>/10240)
212 Sets the number of I<dcache entries> allocated in machine memory for
213 storing information about the chunks in the cache.
215 For a disk cache, the F</usr/vice/cache/CacheItems> file contains one
216 entry for each F<VI<n>> file. By default, one half the number of
217 these entries (but not more that 2,000) are duplicated as dcache entries
218 in machine memory for quicker access.
220 For a memory cache, there is no F<CacheItems> file so all information
221 about cache chunks must be in memory as dcache entries. Thus, there is no
222 default number of dcache entries for a memory cache; instead, the B<afsd>
223 program derives it by dividing the cache size by the chunk size.
225 To set the number of dcache entries, use the B<-dcache> argument; the
226 specified value can exceed the default limit of 2,000. Using this argument
227 is not recommended for either type of cache. Increasing the number of
228 dcache entries for a disk cache sometimes improves performance (because
229 more entries are retrieved from memory rather than from disk), but only
230 marginally. Using this argument for a memory cache requires the issuer to
231 calculate the cache size by multiplying this value by the chunk size.
235 Sets the number of I<stat> entries available in machine memory for caching
236 status information about cached AFS files. The default is 300; use the
237 B<-stat> argument to override the default.
241 If the B<-settime> option is specified, then it randomly selects a file
242 server machine in the local cell as the source for the correct time. Every
243 five minutes thereafter, the local clock is adjusted (if necessary) to
244 match the file server machine's clock. This is not enabled by default. It
245 is recommended, instead, that the Network Time Protocol Daemon be used to
246 synchronize the time.
250 In addition to setting cache configuration parameters, the B<afsd> program
251 starts the following daemons. (On most system types, these daemons appear
252 as nameless entries in the output of the UNIX B<ps> command.)
258 One I<callback> daemon, which handles callbacks. It also responds to the
259 File Server's periodic probes, which check that the client machine is
264 One I<maintenance> daemon, which performs the following tasks:
270 Garbage collects obsolete data (for example, expired tokens) from kernel
279 Refreshes information from read-only volumes once per hour.
283 Does delayed writes for NFS clients if the machine is running the NFS/AFS
290 One I<cache-truncation> daemon, which flushes the cache when free space is
291 required, by writing cached data and status information to the File
296 One I<server connection> daemon, which sends a probe to the File
297 Server every few minutes to check that it is still accessible. If the
298 B<-settime> option is set, it also synchronizes the machine's clock
299 with the clock on a randomly-chosen file server machine. There is
300 always one server connection daemon.
304 One or more I<background> daemons that improve performance by pre-fetching
305 files and performing background (delayed) writes of saved data into AFS.
307 The default number of background daemons is two, enough to service at
308 least five simultaneous users of the machine. To increase the number, use
309 the B<-daemons> argument. A value greater than six is not generally
314 On some system types, one I<Rx listener> daemon, which listens for
319 On some system types, one I<Rx event> daemon, which reviews the Rx
320 system's queue of tasks and performs them as appropriate. Most items in
321 the queue are retransmissions of failed packets.
325 On machines that run AIX with virtual memory (VM) integration, one or more
326 I<VM> daemons (sometimes called I<I/O> daemons, which transfer data
327 between disk and machine memory. The number of them depends on the setting
328 of the B<-biods> and B<-daemons> arguments:
334 If the B<-biods> argument is used, it sets the number of VM daemons.
338 If only the B<-daemons> argument is used, the number of VM daemons is
339 twice the number of background daemons.
343 If neither argument is used, there are five VM daemons.
349 This command does not use the syntax conventions of the AFS command
350 suites. Provide the command name and all option names in full.
354 Before using the B<-shutdown> parameter, use the standard UNIX B<umount>
355 command to unmount the AFS root directory (by convention, F</afs>). On
356 Linux, unloading the AFS kernel module and then loading it again before
357 restarting AFS after B<-shutdown> is recommended.
359 AFS has for years had difficulties with being stopped and restarted
360 without an intervening reboot. While most of these issues have been
361 ironed out, stopping and restarting AFS is not recommended unless
362 necessary and rebooting before restarting AFS is still the safest course
363 of action. This does not apply to Linux; it should be safe to restart the
364 AFS client on Linux without rebooting.
366 In contrast to many client-server applications, not all communication is
367 initiated by the client. When the AFS client opens a file, it registers a
368 callback with the AFS server. If the file changes, the server notifies the
369 client that the file has changed and that all cached copies should be
370 discarded. In order to enable full functionality on the AFS client,
371 including all command-line utilities, the following UDP ports must be open
372 on an firewalls between the client and the server:
375 cachemanager 7001/udp (OpenAFS client. Arla uses 4711/udp)
378 kaserver 7004/udp (not needed with Kerberos v5)
380 reserved 7006/udp (for future use)
383 Additionally, for B<klog> to work through the firewall you need to allow
384 inbound and outbound UDP on ports >1024 (probably 1024<port<2048 would
385 suffice depending on the number of simultaneous B<klog>s).
387 Be sure to set the UDP timeouts on the firewall to be at least twenty
388 minutes for the best callback performance.
396 Enable afsdb support. This will use DNS to lookup the AFSDB record and use
397 that for the database servers for each cell instead of the values in the
398 F<CellServDB> file. This has the advantage of only needing to update one
399 DNS record to reconfigure the AFS clients for a new database server as
400 opposed to touching all of the clients, and also allows one to access a
401 cell without preconfiguring its database servers in F<CellServDB>.
405 Prefer backup volumes for mountpoints in backup volumes. This option means
406 that the AFS client will prefer to resolve mount points to backup volumes
407 when a parent of the current volume is a backup volume. This is similar to
408 the standard behaviour of preferring read-only volumes over read-write
409 volumes when the parent volume is a read-only volume.
411 =item B<-biods> <I<number of I/O daemons>>
413 Sets the number of VM daemons dedicated to performing I/O operations on a
414 machine running a version of AIX with virtual memory (VM) integration. If
415 both this argument and the B<-daemons> argument are omitted, the default
416 is five. If this argument is omitted but the B<-daemons> argument is
417 provided, the number of VM daemons is set to twice the value of the
418 B<-daemons> argument.
420 =item B<-blocks> <I<blocks in cache>>
422 Specifies the number of kilobyte blocks to be made available for caching
423 in the machine's cache directory (for a disk cache) or memory (for a
424 memory cache), overriding the default defined in the third field of the
425 F</usr/vice/etc/cacheinfo> file. For a disk cache, the value cannot exceed
426 95% of the space available in the cache partition. If using a memory
427 cache, do not combine this argument with the B<-dcache> argument, since
428 doing so can possibly result in a chunk size that is not an exponent of 2.
430 =item B<-cachedir> <I<cache directory>>
432 Names the local disk directory to be used as the cache. This value
433 overrides the default defined in the second field of the
434 F</usr/vice/etc/cacheinfo> file.
436 =item B<-chunksize> <I<chunk size>>
438 Sets the size of each cache chunk. The integer provided, which must be
439 from the range C<0> to C<30>, is used as an exponent on the number 2. It
440 overrides the default of 16 for a disk cache (2^16 is 64 KB) and 13 for a
441 memory cache (2^13 is 8 KB). A value of C<0> or less, or greater than
442 C<30>, sets chunk size to the appropriate default. Values less than C<10>
443 (which sets chunk size to a 1 KB) are not recommended. Combining this
444 argument with the B<-dcache> argument is not recommended because it
445 requires that the issuer calculate the cache size that results.
447 B<-chunksize> is an important option when tuning for performance. Setting
448 this option to larger values can increase performance when dealing with
451 =item B<-confdir> <I<configuration directory>>
453 Names a directory other than the F</usr/vice/etc> directory from which to
454 fetch the F<cacheinfo>, F<ThisCell>, and F<CellServDB> configuration
457 =item B<-daemons> <I<number of daemons to use>>
459 Specifies the number of background daemons to run on the machine. These
460 daemons improve efficiency by doing prefetching and background writing of
461 saved data. This value overrides the default of C<2>, which is adequate
462 for a machine serving up to five users. Values greater than C<6> are not
463 generally more effective than C<6>.
465 Note: On AIX machines with integrated virtual memory (VM), the number of
466 VM daemons is set to twice the value of this argument, if it is provided
467 and the B<-biods> argument is not. If both arguments are omitted, there
470 =item B<-dcache> <I<number of dcache entries>>
472 Sets the number of dcache entries in memory, which are used to store
473 information about cache chunks. For a disk cache, this overrides the
474 default, which is 50% of the number of F<VI<n>> files (cache chunks). For
475 a memory cache, this argument effectively sets the number of cache chunks,
476 but its use is not recommended, because it requires the issuer to
477 calculate the resulting total cache size (derived by multiplying this
478 value by the chunk size). Do not combine this argument with the B<-blocks>
479 argument, since doing so can possibly result in a chunk size that is not
484 Generates a highly detailed trace of the B<afsd> program's actions on the
485 standard output stream. The information is useful mostly for debugging
490 The standard behaviour of the AFS client without the B<-dynroot> option is
491 to mount the root.afs volume from the default cell on the F</afs> path. The
492 F</afs> folder and root.afs volume traditionally shows the folders for
493 F<ThisCell> and other cells as configured by the AFS cell administrator.
495 The B<-dynroot> option changes this. Using this option, the AFS client
496 does not mount the root.afs volume on F</afs>. Instead it uses the
497 contents of the F<CellServDB> file to populate the listing of cells in
498 F</afs>. This is known as a DYNamic ROOT. A cell is not contacted until
499 the path F</afs/I<cellname>> if accessed. This functions similarly to an
500 automounter. The main advantage of using B<-dynroot> is that the AFS
501 client will start properly even without network access, whereas the client
502 not using B<-dynroot> will freeze upon startup if cannot contact the
503 default cell specified in F<ThisCell> and mount the root.afs
504 volume. Dynamic root mode is also sometimes called travelling mode because
505 it works well for laptops which don't always have network connectivity.
507 Two advantages of not using dynroot are that listing F</afs> will usually
508 be faster because the contents of F</afs> are limited to what the AFS
509 administrator decides and that symbolic links are traditionally created
510 by the AFS administrator to provide a short name for the cell (i.e.
511 cellname.domain.com is aliased to cellname). However, with dynroot, the
512 local system administrator can limit the default contents of F</afs> by
513 installing a stripped-down F<CellServDB> file, and if dynroot is in effect,
514 the F<CellAlias> file can be used to provide shortname for common AFS cells
515 which provides equivalent functionality to the most commonly used symbolic
518 =item B<-enable_peer_stats>
520 Activates the collection of Rx statistics and allocates memory for their
521 storage. For each connection with a specific UDP port on another machine,
522 a separate record is kept for each type of RPC (FetchFile, GetStatus, and
523 so on) sent or received. To display or otherwise access the records, use
524 the Rx Monitoring API.
526 =item B<-enable_process_stats>
528 Activates the collection of Rx statistics and allocates memory for their
529 storage. A separate record is kept for each type of RPC (FetchFile,
530 GetStatus, and so on) sent or received, aggregated over all connections to
531 other machines. To display or otherwise access the records, use the Rx
536 Return fake values for stat calls on cross-cell mounts. This option makes
537 an C<ls -l> of F</afs> much faster since each cell isn't contacted, and
538 this and the B<-fakestat-all> options are useful on Mac OS X so that the
539 Finder program doesn't try to contact every AFS cell the system knows
542 =item B<-fakestat-all>
544 Return fake values for stat calls on all mounts, not just cross-cell
545 mounts. This and the B<-fakestat> options are useful on Mac OS X so that
546 the Finder program doesn't hang when browsing AFS directories.
548 =item B<-files> <I<files in cache>>
550 Specifies the number of F<VI<n>> files to create in the cache directory
551 for a disk cache, overriding the default that is calculated as described
552 in L<DESCRIPTION>. Each F<VI<n>> file accommodates a chunk of data, and
553 can grow to a maximum size of 64 KB by default. Do not combine this
554 argument with the B<-memcache> argument.
556 =item B<-files_per_subdir> <I<files per cache subdirectory>>
558 Limits the number of cache files in each subdirectory of the cache
559 directory. The value of the option should be the base-two log of the
560 number of cache files per cache subdirectory (so 10 for 1024 files, 14 for
561 16384 files, and so forth).
565 Prints the online help for this command. All other valid options are
568 =item B<-logfile> <I<log file location>>
570 This option is obsolete and no longer has any effect.
572 =item B<-mem_alloc_sleep>
574 Allows sleeps when allocating a memory cache.
578 Initializes a memory cache rather than a disk cache. Do not combine this
579 flag with the B<-files> argument.
581 =item B<-mountdir> <I<mount location>>
583 Names the local disk directory on which to mount the root of the AFS
584 filespace. This value overrides the default defined in the first field of
585 the F</usr/vice/etc/cacheinfo> file. If a value other than the F</afs>
586 directory is used, the machine cannot access the filespace of cells that
591 Do not mount AFS on startup. The afs global mount must be mounted via
592 some other means. This is useful on Mac OS X where /afs is sometimes
593 mounted in /Network/afs like other network file systems.
597 This is enabled by default. It prevents the Cache Manager from
598 synchronizing its clock with the clock on a server machine selected at
599 random by checking the time on the server machine every five minutes.
600 This is the recommended behavior; instead of the AFS Cache Manager, the
601 Network Time Protocol Daemon should be used to synchronize the system
604 =item B<-prealloc> <I<number of preallocated blocks>>
606 Specifies the number of pieces of memory to preallocate for the Cache
607 Manager's internal use. The default initial value is C<400>, but the Cache
608 Manager dynamically allocates more memory as it needs it.
612 Initializes an additional daemon to execute AFS-specific system calls on
613 behalf of NFS client machines. Use this flag only if the machine is an
614 NFS/AFS translator machine serving users of NFS client machines who
615 execute AFS commands.
617 =item B<-rootvol> <I<name of AFS root volume>>
619 Names the read/write volume corresponding to the root directory for the
620 AFS file tree (which is usually the F</afs> directory). This value
621 overrides the default of the C<root.afs> volume. This option is ignored if
622 B<-dynroot> is given.
626 Bind the Rx socket (one interface only).
628 =item B<-rxpck> <I<value for rx_extraPackets>>
630 Set rx_extraPackets to this value. This sets the number of extra Rx
631 packet structures that are available to handle Rx connections. This
632 value should be increased if the "rxdebug 127.0.0.1 -port 7001
633 -rxstats" command shows no free Rx packets. Increasing this value may
634 improve OpenAFS client performance in some circumstances.
638 Enable native AFS time synchronization. This option is the opposite of
639 B<-nosettime> and cannot be used with the B<-nosettime> option.
643 Shuts down the Cache Manager. Before calling B<afsd> with this option,
644 unmount the AFS file system with B<umount>.
646 =item B<-splitcache> <I<RW/RO Ratio>>
648 This allows the user to set a certain percentage of the AFS cache be
649 reserved for read/write content and the rest to be reserved for read-only
650 content. The ratio should be written as a fraction. For example,
651 C<-splitcache 75/25> devotes 75% of your cache space to read/write content
652 and 25% to read-only.
654 =item B<-stat> <I<number of stat entries>>
656 Specifies the number of entries to allocate in the machine's memory for
657 recording status information about the AFS files in the cache. This value
658 overrides the default of C<300>.
662 Generates a detailed trace of the B<afsd> program's actions on the
663 standard output stream.
665 =item B<-volumes> <I<number of volume entries>>
667 Specifies the number of memory structures to allocate for storing volume
668 location information. The default value is C<50>.
672 Has no effect on the operation of the Cache Manager. The behavior it
673 affected in previous versions of the Cache Manager, to perform synchronous
674 writes to the File Server, is now the default behavior. To perform
675 asynchronous writes in certain cases, use the B<fs storebehind> command.
681 The B<afsd> command is normally included in the machine's AFS
682 initialization file, rather than typed at the command shell prompt. For
683 most disk caches, the appropriate form is
687 The following command is appropriate when enabling a machine to act as an
688 NFS/AFS Translator machine serving more than five users.
690 % /usr/vice/etc/afsd -daemons 4 -rmtsys
692 The following command initializes a memory cache and sets chunk size to 16
695 % /usr/vice/etc/afsd -memcache -chunksize 14
697 =head1 PRIVILEGE REQUIRED
699 The issuer must be logged in as the local superuser root.
710 IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
712 This documentation is covered by the IBM Public License Version 1.0. It
713 was converted from HTML to POD by software written by Chas Williams and
714 Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.