Choosing Cache Type, Location, and Size

The default DFS configuration is disk caching. However, the Cache Manager can use a machine memory cache rather than a disk cache. To direct the Cache Manager to use memory caching, use the -memcache option with the dfsd command. When the -memcache option is used, the Cache Manager does no disk caching, even if the machine has a disk available.

The CacheInfo file defines the directory to use for a disk cache and the size of a disk or memory cache. The Cache Manager checks this file at initialization to determine this information. The CacheInfo file contains the following three fields separated by colons:

· A directory on the local disk where the Cache Manager mounts the DCE global namespace. The default entry is the global namespace designation (/...). If /... is not specified, symbolic links to the global namespace fail.

· A local directory that serves as the DFS cache for a disk cache. The Cache Manager creates its cache files in this directory. The default entry is dcelocal/var/adm/dfs/cache. Although the indicated directory is not used with a memory cache, an entry must appear in this field even if memory caching is employed on the machine.

· A definition of the cache size in kilobyte blocks.

Following is an example of a CacheInfo file. The file lists the DCE namespace mounted at the global namespace designation (/...), the dcelocal/var/adm/dfs/cache directory used for the cache, and a defined cache size of 50,000 kilobyte blocks (the machine must have this many blocks available on its disk):

/...:dcelocal/var/adm/dfs/cache:50000