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irix-657m-src/eoe/man/man1m/cfsadmin.1m
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'\"macro stdmacro
.nr X
.TH cfsadmin 1M "8 Aug 1995"
.SH NAME
cfsadmin \- administer disk space used for caching file systems with the Cache File-System (CacheFS)
.SH SYNOPSIS
.B cfsadmin \-c
[
.BI "\-o " cacheFS-parameters
]
.I cache_directory
.br
.B cfsadmin \-d
[
.IR cache_ID "|"
.B all
]
.I cache_directory
.br
.BI "cfsadmin \-l " cache_directory
.br
.B cfsadmin \-u
[
.BI "\-o " cacheFS-parameters
]
.I cache_directory
.br
.BI "cfsadmin \-C " cache_directory
.SH DESCRIPTION
.IX "cfsadmin command" "" "\fLcfsadmin\fP \(em administer disk space used for caching file systems with the Cache File-System (CacheFS)"
.IX "cacheFS" "cfsadmin" "\fLcfsadmin\fP \(em administer disk space used for caching file systems with the Cache File-System (CacheFS)"
.IX "administer disk space used for caching file systems with the Cache File-System (CacheFS)" "" "\fLcfsadmin\fP \(em administer disk space used for caching file systems with the Cache File-System (CacheFS)"
.IX "cfs" "cfsadmin" "\fLcfsadmin\fP \(em administer disk space used for caching file systems with the Cache File-System (CacheFS)"
.IX "file system" "cfs" "" "\fLcfsadmin\fP \(em administer disk space used for caching file systems with the Cache File-System (CacheFS)"
The
.B cfsadmin
command provides administrative tools for managing cached file systems.
Its functions fall into four general categories:
.RS
.TP 2
\(bu
cache creation
.TP
\(bu
deletion of cached file systems
.TP
\(bu
listing of cache contents and statistics
.TP
\(bu
resource parameter adjustment when the file system is unmounted.
.RE
.LP
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.
.LP
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
.B \-l
option includes the cache ID in its listing of information.
You must know the cache ID to delete a cached file system.
.SH OPTIONS
.TP 15
.B \-c
Create a cache under the directory specified by
.IR cache_directory .
This directory must not exist prior to cache creation.
.TP
.B \-d
Remove the file system whose cache ID you specify and release
its resources, or remove all file systems in the cache by
specifying
.BR all .
It is not necessary that a cache be removed by using
.BR cfsadmin .
The cache can simply be removed by using
.BR rm (1).
.TP
.B \-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
.BR du (1M).
.TP
.B \-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
.B \-u
option with no
.B \-o
option sets all parameters to their default values.
.TP
.B \-C
Convert an existing cache to the new format. This consists of converting
the cache IDs from their old form to the new form.
.br
.ne 5
.SS "CacheFS Resource Parameters"
.LP
You can specify the following cacheFS resource parameters
as arguments to the
.B \-o
option. Separate multiple parameters with commas.
.TP 15
.BI 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
.B maxblocks
parameter allows will be available. The default is
.BR 90 .
.br
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.
.TP
.BI hiblocks= n
This sets the high water mark for disk space usage.
The value
.I 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
.BR 85 .
.TP
.BI lowblocks= n
This sets the low water mark for disk space usage.
The value
.I 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
.BR hiblocks .
The default low water mark is
.BR 75 .
.TP 15
.BI 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
.B maxfiles
parameter allows will be available. The default is
.BR 90 .
.TP
.BI hifiles= n
This sets the high water mark for file allocation.
The value
.I 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
.BR 85 .
.TP
.BI lowfiles= n
This sets the low water mark for file allocation.
The value
.I 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
.BR hifiles .
The default low water mark is
.BR 75 .
.LP
The cache parameters may only be changed for unmounted caches. The values,
however, may be adjusted in any direction.
.SH EXAMPLES
The following example creates a cache directory named
.BR /cache :
.RS
.B
example% cfsadmin -c /cache
.RE
.LP
The following example creates a cache named
.B /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.
.LP
.RS
.ft 3
example% cfsadmin \-c \-o maxblocks=60,lowblocks=40,
.ti +5n
hiblocks=50 /cache1
.ft 1
.RE
.LP
The following example lists the contents of a cache directory named
.B /cache3
and provides statistics about resource utilization:
.LP
.RS
.B
example% cfsadmin \-l /cache3
.RE
.LP
The following example removes the cached file system
with cache ID
.B 23
from the cache directory
.B /cache3
and frees its resources (the cache ID is part of the
information returned by
.BR "cfsadmin \-l" ):
.LP
.RS
.B
example% cfsadmin \-d 23 /cache3
.RE
.LP
The following example removes all cached file systems from the cache
directory
.BR /cache3 :
.LP
.RS
.B
example% cfsadmin \-d all /cache3
.RE
.SH "SEE ALSO"
.BR mount (1M),
.BR fstab (4),
.BR rm (4),
.BR du (1M)