System Administration Guide: Devices and File Systems

CacheFS File System Structure and Behavior

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

Table 19–1 CacheFS File System Parameters and Their Default Values


CacheFS File System Parameter	Default Value	Definition
`maxblocks`	90 %	Sets the maximum number of blocks that a CacheFS file system is allowed to claim within the front file system.
`minblocks`	0 %	Sets the minimum number of blocks that a CacheFS file system 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 a CacheFS file system can claim more than the blocks specified by `minblocks`.
`maxfiles`	90 %	Sets the maximum number of available inodes (number of files) that a CacheFS file system is allowed to claim within the front file system.
`minfiles`	0 %	Sets the minimum number of available inodes that a CacheFS file system is allowed to claim within the front file system.
`threshfiles`	85 %	Sets the number of inodes that must be available in the front file system before a CacheFS file system can claim more files than is 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 values if you have some room in the front file system that is not used by the cache, and you want to use it for some other file system. You do so by using the cfsadmin command. For example:

$ cfsadmin -o maxblocks=60