cfsadmin(1M) (man pages section 1M: System Administration Commands)

man pages section 1M: System Administration Commands

cfsadmin(1M)

Name

cfsadmin– administer disk space used for caching file systems with the Cache File-System (CacheFS)

Synopsis

cfsadmin -c [-o cacheFS-parameters] cache_directory

cfsadmin -d {cache_ID | all} cache_directory

cfsadmin -l cache_directory

cfsadmin -s {mntpt1 ....} | all

cfsadmin -u [-o cacheFS-parameters] cache_directory

Description

The cfsadmin command provides the following functions:

cache creation
deletion of cached file systems
listing of cache contents and statistics
resource parameter adjustment when the file system is unmounted.

You must always supply an option for cfsadmin. For each form of the command except -s, 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

The following options are supported:

-c [ -o cacheFS-parameters ] cache_directory

Create a cache under the directory specified by cache_directory. This directory must not exist prior to cache creation.

-d { cache_ID | all } cache_directory

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(1M) command to correct the resource counts for the cache.

As indicated by the syntax above, you must supply either a cache_ID or all, in addition to cache_directory.

-l cache_directory

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 { mntpt1 ... } | all

Request a consistency check on the specified file system (or all cachefs mounted file systems). The -s option only works 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 does not result in a sudden "storm" of consistency checks.

As indicated by the syntax above, you must supply one or more mount points, or all.

-u [ -o cacheFS-parameters ] cache_directory

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 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.

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 is 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 is 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. If CacheFS does not have exclusive use of the front file system, there is no guarantee that all the inodes the maxfiles parameter allows is 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 is 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. 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.

Currently maxfilesize is ignored by cachefs, therefore, setting it has no effect.

Operands

cache_directory: The directory under which the cache is actually stored.
mntpt1: The directory where the CacheFS is mounted.

Usage

See largefile(5) for the description of the behavior of cfsadmin when encountering files greater than or equal to 2 Gbyte ( 2³¹ bytes).

Examples

Example 1 Creating a Cache Directory

The following example creates a cache directory named /cache:

example# cfsadmin -c /cache

Example 2 Creating a 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 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.

example# cfsadmin -c -o maxblocks=60,minblocks=40,threshblocks=50 /cache1

Example 3 Changing the `maxfilesize` Parameter

The following example changes the maxfilesize parameter for the cache directory /cache2 to 2 megabytes:

example# cfsadmin -u -o maxfilesize=2 /cache2

Example 4 Listing the Contents of a Cache Directory

The following example lists the contents of a cache directory named /cache3 and provides statistics about resource utilization:

example# cfsadmin -l /cache3

Example 5 Removing a Cached File System

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

Example 6 Removing All Cached File Systems

The following example removes all cached file systems from the cache directory /cache3:

example# cfsadmin -d all /cache3

Example 7 Checking for Consistency in File Systems

The following example checks for consistency all file systems mounted with demandconst enabled. No errors are reported if no demandconst file systems were found.

example# cfsadmin -s all

Exit Status

The following exit values are returned:

0: Successful completion.
1: An error occurred.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Availability	SUNWcsu