Erik Mol <kokkers@xxxxxxxxx> wrote: > Still some of the CacheFS parts are still a bit vague to me. > FScache!=CacheFS!=Cachefiles(d) Have you looked at my OLS presentation? It's at: http://people.redhat.com/~dhowells/fscache/fscache-ols2006.odp > FS-Cache is a part of the Linux Kernel which intermediates between 'network > based filesystems' (AFS/NFS) and a cache back-end. > FS-Cache is designed to work with a cache back-end of choice. With one or more back-ends of choice, yes. You aren't limited to one. > Cache back-ends: > CacheFS can act as a cache back-end to FS-Cache and runs on top of a block > device thus providing its own filesystem. > CacheFiles can act as a cache back-end to FS-Cache and runs in directory on > top of another filesystem. Both correct. > We are using and talking about CacheFiles(d), right? Probably. CacheFiles is the cache back-end, comprising a module and a userspace program (called cachefilesd) that manages the cache. > Since I do not have the knowledge to modify a RHEL4 distribution to get it to > work with FS-Cache I decided to try out RHEL 5 Beta 2. You'd have to replace the kernel in RHEL4 with something much more recent. > Dec 6 11:59:37 RHEL5B2 cachefilesd[2117]: Failed to check object's in-use > state: errno 95 (Operation not supported) That very much suggests that cachefilesd was unable to access user xattrs on a file. You could try turning up the debugging level on cachefilesd (-d), telling it to log to stderr (-s) and running it in command line mode (-n) and then capturing the output: cachefilesd -dsn | tee cache.log to see what it's doing. David
