CacheFS Overview

CacheFS is a general purpose filesystem caching mechanism that improves NFS client and server performance. CacheFS client performance is improved by caching data to a faster local filesystem instead of going over the wire to a slow server or on a slow network. This results in reduced server and network load because the clients send fewer requests to the server.

In an NFS environment, CacheFS:

performs local disk caching of filesystems which enables the client systems to become less reliant on the server
improves performance of clients on slow networks
increases the number of clients that can be supported by a single server
decreases the overall server load which can result in better server performance.

When data is read from a cached NFS-mounted filesystem for the first time, it results in some overhead when CacheFS writes the data to its local cache. After the data is written to the cache, read performance for the cached data improves significantly. CacheFS improves read performance for data that is read more than once. However, it does not improve NFS write performance. Therefore, good candidates for cached filesystems include manpages and executable programs, which are read multiple times though rarely modified.

By default, CacheFS maintains consistency between the cached filesystem and the remote filesystem, using a consistency checking model similar to that of standard NFS (polling for changes in file attributes).




	NOTE: CacheFS cannot be used with NFSv4.

CacheFS Overview

Technical documentation

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