Provided by: openafs-client_1.4.1-2_i386 bug

NAME

       afsd - Initializes the Cache Manager and starts related daemons

SYNOPSIS

       afsd << [-blocks <1024 byte blocks in cache] >>>
            << [-files <files in cache] >>>
            << [-rootvol <name of AFS root volume] >>>
            << [-stat <number of stat entries] >>>
            [-memcache] << [-cachedir <cache directory] >>>
            << [-mountdir <mount location] >>>
            << [-daemons <number of daemons to use] >>>
            [-nosettime] [-verbose] [-rmtsys] [-debug]
            << [-chunksize <log(2) of chunk size] >>>
            << [-dcache <number of dcache entries] >>>
            << [-volumes <number of volume entries] >>>
            << [-biods <number of bkg I/O daemons (aix vm)] >>>
            << [-prealloc <number of Äôsmall‚Äô preallocated blocks] >>>
            << [-confdir <configuration directory] >>>
            << [-logfile <Place to keep the CM log] >>>
            [-waitclose] [-shutdown] [-enable_peer_stats]
            [-enable_process_stats] [-help]

DESCRIPTION

       The afsd command initializes the Cache Manager on an AFS client machine
       by transferring AFS-related configuration information into kernel
       memory and starting several daemons. More specifically, the afsd
       command performs the following actions:

       ·   Sets a field in kernel memory that defines the machine’s cell
           membership. Some Cache Manager-internal operations and system calls
           consult this field to learn which cell to execute in. (The AFS
           command interpreters refer to the /etc/openafs/ThisCell file
           instead.) This information is transferred into the kernel from the
           /etc/openafs/ThisCell file and cannot be changed until the afsd
           program runs again.

       ·   Places in kernel memory the names and Internet addresses of the
           database server machines in the local cell and (optionally) foreign
           cells. The appearance of a cell’s database server machines in this
           list enables the Cache Manager to contact them and to access files
           in the cell. Omission of a cell from this list, or incorrect
           information about its database server machines, prevents the Cache
           Manager from accessing files in it.

           The list of database server machines is transferred into the kernel
           from the /etc/openafs/CellServDB file. After initialization, use
           the fs newcell command to change the kernel-resident list without
           having to reboot.

       ·   Mounts the root of the AFS filespace on a directory on the
           machine’s local disk, according to either the first field in the
           /etc/openafs/cacheinfo file (the default) or the afsd command’s
           -mountdir argument. The conventional value is /afs.

       ·   Determines which volume to mount at the root of the AFS file tree.
           The default is the volume root.afs; use the -rootvol argument to
           override it. Although the base (read/write) form of the volume name
           is the appropriate value, the Cache Manager has a bias for
           accessing the read-only version of the volume (by convention,
           root.afs.readonly) if it is available.

       ·   Configures the cache on disk (the default) or in machine memory if
           the -memcache argument is provided. In the latter case, the afsd
           program allocates space in machine memory for caching, and the
           Cache Manager uses no disk space for caching even if the machine
           has a disk.

       ·   Defines the name of the local disk directory devoted to caching,
           when the -memcache argument is not used. If necessary, the afsd
           program creates the directory (its parent directory must already
           exist). It does not remove the directory that formerly served this
           function, if one exists.

           The second field in the /etc/openafs/cacheinfo file is the source
           for this name, and the standard value is the /usr/vice/cache
           directory. Use the -cachedir argument to override the value in the
           cacheinfo file.

       ·   Sets the size of the cache. The default source for the value is the
           third field in the /etc/openafs/cacheinfo file, which specifies a
           number of kilobytes.

           For a memory cache, the following arguments to the afsd command
           override the value in the cacheinfo file:

       ·       The -blocks argument, to specify a different number of kilobyte
               blocks.

       ·       The -dcache and -chunksize arguments together, to set both the
               number of dcache entries and the chunk size (see below for
               definition of these parameters). In this case, the afsd program
               derives cache size by multiplying the two values. Using this
               combination is not recommended, as it requires the issuer to
               perform the calculation beforehand to determine the resulting
               cache size.

       ·       The -dcache argument by itself. In this case, the afsd program
               derives cache size by multiplying the value specified by the
               -dcache argument by the default memory cache chunk size of
               eight kilobytes. Using this argument is not recommended, as it
               requires the issuer to perform the calculation beforehand to
               determine the resulting cache size.

               For satisfactory memory cache performance, the specified value
               must leave enough memory free to accommodate all other
               processes and commands that can run on the machine. If the
               value exceeds the amount of memory available, the afsd program
               exits without initializing the Cache Manager and produces the
               following message on the standard output stream:

                  afsd: memCache allocation failure at <number> KB

               where <number> is how many kilobytes were allocated just before
               the failure.

               For a disk cache, use the -blocks argument to the afsd command
               to override the value in the cacheinfo file. The value
               specified in either way sets an absolute upper limit on cache
               size; values provided for other arguments (such as -dcache and
               -chunksize) never result in a larger cache. The afsd program
               rejects any setting larger than 95% of the partition size, and
               exits after generating an error message on the standard output
               stream, because the cache implementation itself requires a
               small amount of disk space and overfilling the partition can
               cause the client machine to panic.

               To change the size of a disk cache after initialization without
               rebooting, use the fs setcachesize command; the setting
               persists until the afsd command runs again or the fs
               setcachesize command is reissued. The fs setcachesize command
               does not work for memory caches.

       ·   Sets the size of each cache chunk, and by implication the amount of
           data that the Cache Manager requests at a time from the File Server
           (how much data per fetch RPC, since AFS uses partial file
           transfer).

           For a disk cache, a chunk is a Vn file and this parameter sets the
           maximum size to which each one can expand; the default is 64 KB.
           For a memory cache, each chunk is a collection of contiguous memory
           blocks; the default is size is 8 KB.

           To override the default chunk size for either type of cache, use
           the -chunksize argument to provide an integer to be used as an
           exponent of two; see the OPTIONS manpage for details. For a memory
           cache, if total cache size divided by chunk size leaves a
           remainder, the afsd program rounds down the number of dcache
           entries, resulting in a slightly smaller cache.

       ·   Sets the number of chunks in the cache. For a memory cache, the
           number of chunks is equal to the cache size divided by the chunk
           size.  For a disk cache, the number of chunks (Vn files) is set to
           the largest of the following unless the -files argument is used to
           set the value explicitly:

       ·       100

       ·       1.5 times the result of dividing cache size by chunk size
               (cachesize/chunksize * 1.5)

       ·       The result of dividing cachesize by 10 KB (cachesize/10240)

       ·   Sets the number of dcache entries allocated in machine memory for
           storing information about the chunks in the cache.

           For a disk cache, the /usr/vice/cache/CacheItems file contains one
           entry for each Vn file. By default, one half the number of these
           entries (but not more that 2,000) are duplicated as dcache entries
           in machine memory for quicker access.

           For a memory cache, there is no CacheItems file so all information
           about cache chunks must be in memory as dcache entries.  Thus,
           there is no default number of dcache entries for a memory cache;
           instead, the afsd program derives it by dividing the cache size by
           the chunk size.

           To set the number of dcache entries, use the -dcache argument; the
           specified value can exceed the default limit of 2,000. Using this
           argument is not recommended for either type of cache. Increasing
           the number of dcache entries for a disk cache sometimes improves
           performance (because more entries are retrieved from memory rather
           than from disk), but only marginally. Using this argument for a
           memory cache requires the issuer to calculate the cache size by
           multiplying this value by the chunk size.

       ·   Sets the number of stat entries available in machine memory for
           caching status information about cached AFS files. The default is
           300; use the -stat argument to override the default.

       ·   Randomly selects a file server machine in the local cell as the
           source for the correct time. Every five minutes thereafter, the
           local clock is adjusted (if necessary) to match the file server
           machine’s clock.

           Use the -nosettime flag to prevent the afsd command from selecting
           a time standard. This is recommended only on file server machines
           that are also acting as clients. File server machines maintain the
           correct time using the Network Time Protocol Daemon instead.

       In addition to setting cache configuration parameters, the afsd program
       starts the following daemons. (On most system types, these daemons
       appear as nameless entries in the output of the UNIX ps command.)

       ·   One callback daemon, which handles callbacks. It also responds to
           the File Server’s periodic probes, which check that the client
           machine is still alive.

       ·   One maintenance daemon, which performs the following tasks:

       ·       Garbage collects obsolete data (for example, expired tokens)
               from kernel memory.

       ·       Synchronizes files.

       ·       Refreshes information from read-only volumes once per hour.

       ·       Does delayed writes for NFS clients if the machine is running
               the NFS/AFS Translator.

       ·   One cache-truncation daemon, which flushes the cache when free
           space is required, by writing cached data and status information to
           the File Server.

       ·   One server connection daemon, which sends a probe to the File
           Server every few minutes to check that it is still accessible. It
           also synchronizes the machine’s clock with the clock on a randomly-
           chosen file server machine, unless the -nosettime flag is used.
           There is always one server connection daemon.

       ·   One or more background daemons that improve performance by pre-
           fetching files and performing background (delayed) writes of saved
           data into AFS.

           The default number of background daemons is two, enough to service
           at least five simultaneous users of the machine. To increase the
           number, use the -daemons argument. A value greater than six is not
           generally necessary.

       ·   On some system types, one Rx listener daemon, which listens for
           incoming RPCs.

       ·   On some system types, one Rx event daemon, which reviews the Rx
           system’s queue of tasks and performs them as appropriate. Most
           items in the queue are retransmissions of failed packets.

       ·   On machines that run AIX with virtual memory (VM) integration, one
           or more VM daemons (sometimes called I/O daemons, which transfer
           data between disk and machine memory. The number of them depends on
           the setting of the -biods and -daemons arguments:

       ·       If the -biods argument is used, it sets the number of VM
               daemons.

       ·       If only the -daemons argument is used, the number of VM daemons
               is twice the number of background daemons.

       ·       If neither argument is used, there are five VM daemons.

       This command does not use the syntax conventions of the AFS command
       suites. Provide the command name and all option names in full.

CAUTIONS

       Do not use the -shutdown parameter. It does not shutdown the Cache
       Manager effectively. Instead, halt Cache Manager activity by using the
       standard UNIX umount command to unmount the AFS root directory (by
       convention, /afs). The machine must then be rebooted to reinitialize
       the Cache Manager.

OPTIONS

       -blocks <blocks in cache>
           Specifies the number of kilobyte blocks to be made available for
           caching in the machine’s cache directory (for a disk cache) or
           memory (for a memory cache), overriding the default defined in the
           third field of the /etc/openafs/cacheinfo file. For a disk cache,
           the value cannot exceed 95% of the space available in the cache
           partition. If using a memory cache, do not combine this argument
           with the -dcache argument, since doing so can possibly result in a
           chunk size that is not an exponent of 2.

       -files <files in cache>
           Specifies the number of Vn files to create in the cache directory
           for a disk cache, overriding the default that is calculated as
           described in the DESCRIPTION manpage. Each Vn file accommodates a
           chunk of data, and can grow to a maximum size of 64 KB by default.
           Do not combine this argument with the -memcache argument.

       -rootvol <name of AFS root volume>
           Names the read/write volume corresponding to the root directory for
           the AFS file tree (which is usually the /afs directory). This value
           overrides the default of the root.afs volume.

       -stat <number of stat entries>
           Specifies the number of entries to allocate in the machine’s memory
           for recording status information about the AFS files in the cache.
           This value overrides the default of 300.

       -memcache
           Initializes a memory cache rather than a disk cache. Do not combine
           this flag with the -files argument.

       -cachedir <cache directory>
           Names the local disk directory to be used as the cache. This value
           overrides the default defined in the second field of the
           /etc/openafs/cacheinfo file.

       -mountdir <mount location>
           Names the local disk directory on which to mount the root of the
           AFS filespace. This value overrides the default defined in the
           first field of the /etc/openafs/cacheinfo file. If a value other
           than the /afs directory is used, the machine cannot access the
           filespace of cells that do use that value.

       -daemons <number of daemons to use>
           Specifies the number of background daemons to run on the machine.
           These daemons improve efficiency by doing prefetching and
           background writing of saved data. This value overrides the default
           of 2, which is adequate for a machine serving up to five users.
           Values greater than 6 are not generally more effective than 6.

           Note: On AIX machines with integrated virtual memory (VM), the
           number of VM daemons is set to twice the value of this argument, if
           it is provided and the -biods argument is not. If both arguments
           are omitted, there are five VM daemons.

       -nosettime
           Prevents the Cache Manager from synchronizing its clock with the
           clock on a server machine selected at random, by checking the time
           on the server machine every five minutes. Use this flag only on a
           machine that is already using another time synchronization protocol
           (for example, a server machine that is running the runntp process).

       -verbose
           Generates a detailed trace of the afsd program’s actions on the
           standard output stream.

       -rmtsys
           Initializes an additional daemon to execute AFS-specific system
           calls on behalf of NFS client machines. Use this flag only if the
           machine is an NFS/AFS translator machine serving users of NFS
           client machines who execute AFS commands.

       -debug
           Generates a highly detailed trace of the afsd program’s actions on
           the standard output stream. The information is useful mostly for
           debugging purposes.

       -chunksize <chunk size>
           Sets the size of each cache chunk. The integer provided, which must
           be from the range 0 to 30, is used as an exponent on the number 2.
           It overrides the default of 16 for a disk cache (2^16 is 64 KB) and
           13 for a memory cache (2^13 is 8 KB). A value of 0 or less, or
           greater than 30, sets chunk size to the appropriate default. Values
           less than 10 (which sets chunk size to a 1 KB) are not recommended.
           Combining this argument with the -dcache argument is not
           recommended because it requires that the issuer calculate the cache
           size that results.

       -dcache <number of dcache entries>
           Sets the number of dcache entries in memory, which are used to
           store information about cache chunks. For a disk cache, this
           overrides the default, which is 50% of the number of Vn files
           (cache chunks). For a memory cache, this argument effectively sets
           the number of cache chunks, but its use is not recommended, because
           it requires the issuer to calculate the resulting total cache size
           (derived by multiplying this value by the chunk size). Do not
           combine this argument with the -blocks argument, since doing so can
           possibly result in a chunk size that is not an exponent of 2.

       -volumes <number of volume entries>
           Specifies the number of memory structures to allocate for storing
           volume location information. The default value is 50.

       -biods <number of I/O daemons>
           Sets the number of VM daemons dedicated to performing I/O
           operations on a machine running a version of AIX with virtual
           memory (VM) integration.  If both this argument and the -daemons
           argument are omitted, the default is five. If this argument is
           omitted but the -daemons argument is provided, the number of VM
           daemons is set to twice the value of the -daemons argument.

       -prealloc <number of preallocated blocks>
           Specifies the number of pieces of memory to preallocate for the
           Cache Manager’s internal use. The default initial value is 400, but
           the Cache Manager dynamically allocates more memory as it needs it.

       -confdir <configuration directory>
           Names a directory other than the /etc/openafs directory from which
           to fetch the cacheinfo, ThisCell, and CellServDB configuration
           files.

       -logfile <log file location>
           Is obsolete and has no real effect. It specifies an alternate file
           in which to record a type of trace that the Cache Manager no longer
           generates; the default value is /etc/openafs/AFSLog.

       -waitclose
           Has no effect on the operation of the Cache Manager. The behavior
           it affected in previous versions of the Cache Manager, to perform
           synchronous writes to the File Server, is now the default behavior.
           To perform asynchronous writes in certain cases, use the fs
           storebehind command.

       -shutdown
           Shuts down the Cache Manager, but not in the most effective
           possible way. Do not use this flag.

       -enable_peer_stats
           Activates the collection of Rx statistics and allocates memory for
           their storage. For each connection with a specific UDP port on
           another machine, a separate record is kept for each type of RPC
           (FetchFile, GetStatus, and so on) sent or received. To display or
           otherwise access the records, use the Rx Monitoring API.

       -enable_process_stats
           Activates the collection of Rx statistics and allocates memory for
           their storage. A separate record is kept for each type of RPC
           (FetchFile, GetStatus, and so on) sent or received, aggregated over
           all connections to other machines. To display or otherwise access
           the records, use the Rx Monitoring API.

       -help
           Prints the online help for this command. All other valid options
           are ignored.

EXAMPLES

       The afsd command is normally included in the machine’s AFS
       initialization file, rather than typed at the command shell prompt. For
       most disk caches, the appropriate form is

          /etc/openafs/afsd

       The following command is appropriate when enabling a machine to act as
       an NFS/AFS Translator machine serving more than five users.

          /etc/openafs/afsd -daemons 4 -rmtsys

       The following command initializes a memory cache and sets chunk size to
       16 KB (2^14).

          /etc/openafs/afsd -memcache -chunksize 14

PRIVILEGE REQUIRED

       The issuer must be logged in as the local superuser root.

SEE ALSO

       the afs_cache(5) manpage, the CellServDB(5) manpage, the cacheinfo(5)
       manpage

COPYRIGHT

       IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

       This documentation is covered by the IBM Public License Version 1.0.
       It was converted from HTML to POD by software written by Chas Williams
       and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.