[OpenAFS-devel] Patch to implement default tuning proposal discussed a while ago

[Troy Benjegerdes]

On Mon, Aug 15, 2005 at 08:21:17AM -0400, chas williams - CONTRACTOR wrote:
> In message <20050814033736.GI16924@kalmia.hozed.org>,Troy Benjegerdes writes:
> >How do you measure size of files in the cache? What do we lose by having
> >the average file size being too big?
> 
> you could just examine the files in /usr/vice/cache (or whatever).
> if -files is based on the cachesize/avg file size, this gives an
> upper limit on the number of files in the cache.

On my two Imap servers, one with 8G and the other with a 10G afs cache,
I get an interesting distribution..

http://scl.ameslab.gov/~troy/imap-afscache-sizes.png

It looks like over half of the cache files are zero-length on both
machines, and the default chunk size wound up being 64K.

I'm running with the following afsd command line (which is what the
debian packages decided to set it too.. I'll happill take suggestions on 
better optimizations, or how to find out what's thrashing)

/usr/sbin/afsd -stat 2000 -dcache 800 -daemons 3 -volumes 70 -fakestat
-afsdb -nosettime