NAME
cfsadmin — administer disk space used for caching file systems with the Cache File-System (CacheFS)
SYNOPSIS
/usr/sbin/cfsadmin -c
[ -o
CacheFS-parameters ]
cache_directory
/usr/sbin/cfsadmin -d
{ cache_ID |
all }
cache_directory
/usr/sbin/cfsadmin -l cache_directory
/usr/sbin/cfsadmin -s
{ mntpt1... }
| all
/usr/sbin/cfsadmin -u
[ -o
CacheFS-parameters ]
cache_directory
DESCRIPTION
The
cfsadmin
command provides the following functions:
deletion of cached file systems
listing of cache contents and statistics
resource parameter adjustment when the file system is unmounted.
For each form of the command, with the exception of the
-s form,
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.
For the
-s form
of the command, you must specify a mount point.
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.
Options
- -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.
After deleting a file system from the cache, you must run the
fsck_cachefs
command to correct the resource counts for the cache.
- -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 resource utilization
and cache resource parameters.
- -s
Request a consistency check on the specified file system
(or all CacheFS mounted file systems).
The
-s
option will only work if
the cache file system was mounted with
demandconst
enabled (see
mount_cachefs(1M)).
Each file in the specified
cache file system is checked for consistency with its corresponding
file in the back file system.
Note that the consistency check is performed file by file
as files are accessed.
If no files are accessed, no checks are performed.
Use of this option will not result in a sudden "storm"
of consistency checks.
- -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.
Operands
- cache_directory
The directory under which the cache is actually stored.
- cache_ID
Cache ID is a string that specifies a particular instance
of a cache.
- mntpt1
The directory under which the CacheFS is mounted.
CacheFS Resource Parameters
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.
- minblocks=n
Minimum amount of storage space,
expressed as a percentage of the total number of blocks in the
front file system, that CacheFS is always allowed to use without
limitation by its internal control mechanisms.
If CacheFS does not have exclusive use of the front file system,
there is no guarantee that all the space the
minblocks
parameter attempts to reserve will be available.
The default is
0.
- threshblocks=n
A percentage of the total blocks in the front file system
beyond which CacheFS cannot claim resources once its block usage
has reached the level specified by
minblocks.
The default is
85.
- 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.
CacheFS may automatically increase this parameter
when being used on a VxFS 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.
- minfiles=n
Minimum number of files,
expressed as a percentage of the total number of inodes in the
front file system, that CacheFS is always allowed to use without
limitation by its internal control mechanisms.
If CacheFS does not have exclusive use of the front file system,
there is no guarantee that all the inodes the
minfiles
parameter attempts to reserve will be available.
The default is
0.
- threshfiles=n
A percentage of the total inodes in the front file system
beyond which CacheFS cannot claim inodes once its usage
has reached the level specified by
minfiles.
The default is
85.
- maxfilesize=n
Largest file size, expressed in megabytes, that CacheFS is allowed
to cache.
The default is
3.
Currently,
maxfilesize
is ignored by CacheFS; therefore, setting it
will have no effect.
Note: You cannot decrease the block or inode allotment for a cache.
To decrease the size of a cache, you must remove
it and create it again with different parameters.
RETURN VALUE
cfsadmin
returns the following values:
- 0
Successful completion.
- 1
An error occurred.
EXAMPLES
Create a cache directory named
/cache:
Create a cache named
/cache1
that can claim a maximum of 60 percent of the blocks
in the front file system, can use 40 percent of the front
file system blocks without interference by CacheFS internal
control mechanisms, and has a threshold value of 50 percent.
The threshold value indicates that after CacheFS reaches its
guaranteed minimum, it cannot claim more space if 50 percent of the
blocks in the front file system are already used.
cfsadmin -c -o maxblocks=60,minblocks=40,threshblocks=50 /cache1
Change the
maxfilesize
parameter for the cache directory
/cache2
to 2 megabytes:
cfsadmin -u -o maxfilesize=2 /cache2
List the contents of a cache directory named
/cache3
and provides statistics about resource utilization:
Remove 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):
Remove all cached file systems from the cache
directory
/cache3:
Check for consistency of all filesystems mounted
with
demandconst
enabled.
No errors will be reported if no
demandconst
filesystems are found.
AUTHOR
cfsadmin
was developed by Sun Microsystems, Inc.
Printable version
