System Administration Guide, Volume 1

The Cache Structure and Behavior

Each cache has a set of parameters that determines how it behaves and its structure. The parameters are set to default values which are listed in Table 37-5. The default values specify that the entire front file system is used for caching, which is the recommended method of caching file systems.

Table 37-5 Cache Parameters and Their Default Values


Cache Parameter	Default Value	Definition
`maxblocks`	90%	Sets the maximum number of blocks that CacheFS is allowed to claim within the front file system.
`minblocks`	0%	Sets the minimum number of blocks that CacheFS is allowed to claim within the front file system.
`threshblocks`	85%	Sets the number of blocks that must be available in the front file system before CacheFS can claim more than the blocks specified by minblocks.
`maxfiles`	90%	Sets the maximum number of available inodes (number of files) that CacheFS is allowed to claim within the front file system.
`minfiles`	0%	Sets the minimum number of available inodes (number of files) that CacheFS is allowed to claim within the front file system.
`threshfiles`	85%	Sets the number of inodes (number of files) that must be available in the front file system before CacheFS can claim more than the files specified in minfiles.

Typically, you should not change any of these parameter values. They are set to default values to achieve optimal cache behavior. However, you might want to modify the maxblocks and maxfiles settings if you have some room in the front file system that is not used by the cache, and you wish to use it for some other file system. You do this using the cfsadmin(1M) command. For example:

$ cfsadmin -o maxblocks=60