cfsadmin(1M) cfsadmin(1M)
cfsadmin - administer disk space used for caching file systems with the
Cache File-System (CacheFS)
cfsadmin -c [ -o cacheFS-parameters ] cache_directory
cfsadmin -d [ cache_ID| all ] cache_directory
cfsadmin -l cache_directory
cfsadmin -u [ -o cacheFS-parameters ] cache_directory
cfsadmin -C cache_directory
The cfsadmin command provides administrative tools for managing cached
file systems. Its functions fall into four general categories:
o cache creation
o deletion of cached file systems
o listing of cache contents and statistics
o resource parameter adjustment when the file system is unmounted.
For each form of the command, you must specify a cache directory, that
is, the directory under which the cache is actually stored. A path name
in the front file system identifies the cache directory.
You can specify a cache ID when you mount a file system with CacheFS, or
you can let the system generate one for you. The -l option includes the
cache ID in its listing of information. You must know the cache ID to
delete a cached file system.
-c Create a cache under the directory specified by
cache_directory. This directory must not exist prior to
cache creation.
-d Remove the file system whose cache ID you specify and
release its resources, or remove all file systems in the
cache by specifying all. It is not necessary that a cache
be removed by using cfsadmin. The cache can simply be
removed by using rm(1).
-l List file systems stored in the specified cache, as well
as statistics about them. Each cached file system is
listed by cache ID. The statistics document cache resource
parameters. The block allocation limits are given as
percentages and in 512-byte block units. Cache
utilization may be accurately reported with du(1M).
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cfsadmin(1M) cfsadmin(1M)
-u Update resource parameters of the specified cache
directory. Parameter values can only be increased. To
decrease the values, you must remove the cache and
recreate it. All file systems in the cache directory must
be unmounted when you use this option. Changes will take
effect the next time you mount any file system in the
specified cache directory. The -u option with no -o
option sets all parameters to their default values.
-C Convert an existing cache to the new format. This
consists of converting the cache IDs from their old form
to the new form.
CacheFS Resource Parameters [Toc] [Back]
You can specify the following cacheFS resource parameters as arguments to
the -o option. Separate multiple parameters with commas.
maxblocks=n Maximum amount of storage space that CacheFS can use,
expressed as a percentage of the total number of blocks in
the front file system. If CacheFS does not have exclusive
use of the front file system, there is no guarantee that
all the space the maxblocks parameter allows will be
available. The default is 90.
This value defines an upper bound on the space available
to cachefs. Once the utilization of the front file system
(cachefs and non-cachefs) reaches this value, cachefs will
no longer allocate space for the caching of files.
hiblocks=n This sets the high water mark for disk space usage. The
value n is expressed as a percentage of the total number
of blocks in the front front file system. When the
utilization of the front file system as a whole (cachefs
and non-cachefs) reaches the high water mark, cachefs will
begin removing cached files. Enough files will be removed
to bring the front file system usage down to the low water
mark. The default high water mark is 85.
lowblocks=n This sets the low water mark for disk space usage. The
value n is expressed as a percentage of the total number
of blocks in the front front file system. This value is
used for cache replacement as described above for
hiblocks. The default low water mark is 75.
maxfiles=n Maximum number of files that CacheFS can use, expressed as
a percentage of the total number of inodes in the front
file system. If CacheFS does not have exclusive use of
the front file system, there is no guarantee that all the
inodes the maxfiles parameter allows will be available.
The default is 90.
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hifiles=n This sets the high water mark for file allocation. The
value n is expressed as a percentage of the total number
of blocks in the front front file system. When the high
water mark is reached, cachefs will begin removing cached
files. Enough files will be removed to bring the front
file system usage down to the low water mark. The default
high water mark is 85.
lowfiles=n This sets the low water mark for file allocation. The
value n is expressed as a percentage of the total number
of blocks in the front front file system. This value is
used for cache replacement as described above for hifiles.
The default low water mark is 75.
The cache parameters may only be changed for unmounted caches. The
values, however, may be adjusted in any direction.
The following example creates a cache directory named /cache:
example% cfsadmin -c /cache
The following example creates a cache named /cache1 that can claim a
maximum of 60 percent of the blocks in the front file system, can use 50
percent of the front file system blocks without interference by CacheFS
internal control mechanisms (i.e., replacement). Once this allocation
level has been reached, cachefs will remove cached files until the low
water value of 40 percent is reached.
example% cfsadmin -c -o maxblocks=60,lowblocks=40,
hiblocks=50 /cache1
The following example lists the contents of a cache directory named
/cache3 and provides statistics about resource utilization:
example% cfsadmin -l /cache3
The following example removes the cached file system with cache ID 23
from the cache directory /cache3 and frees its resources (the cache ID is
part of the information returned by cfsadmin -l):
example% cfsadmin -d 23 /cache3
The following example removes all cached file systems from the cache
directory /cache3:
example% cfsadmin -d all /cache3
mount(1M), fstab(4), rm(4), du(1M)
PPPPaaaaggggeeee 3333 [ Back ]
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