[OpenAFS] Re: improving cache partition performance

Andrew Deason adeason@sinenomine.net
Tue, 30 Aug 2011 10:30:46 -0500

On Mon, 29 Aug 2011 19:39:14 -0400
Jason Edgecombe <jason@rampaginggeek.com> wrote:

> I was told that noatime is bad for an AFS cache partition because AFS 
> uses the atime to know when the cache entry was last accessed.
> Is that the case?

atime is only read when the client starts up and scans the extant cache
files. And the only thing we use it for is when determining which cache
entries to kick out when we get full.

It's not going to break if you turn it off, and the atime accuracy is a
little dubious anyway, since we don't issue a read for the cache fs on
every read from afs. I wouldn't think any benefit from the cache
eviction decisions would outweigh the penalties for atime updates in the
long run.

Andrew Deason