[OpenAFS] Cache size limit?

[Frank Burkhardt]

Hi,

On Mon, Mar 22, 2010 at 02:38:50PM +0000, Stephen Quinney wrote:
> I was wondering if there are set limits on the AFS cache size for a
> client? Or are there  any limiting factors which mean it is not worth
> going beyond a certain point? In this case, this is on a 32bit Linux
> machine but I am also interested in getting an answer for the same
> question for x64_64 Linux. The machine is being used by multiple users
> simultaneously to do big (i.e. large memory & cpu usage, lots of
> filesystem access, long running) computation jobs so I am trying to
> work out the best way to optimise the AFS access.

I've got about 100 linux hosts (x86_64,Debian Lenny,OA 1.4.10) here using a
30GB disk cache. However, I would be interested in some information about
cache limits, too. One of my user is very dissapointed about our AFS'
performance. So I put an additional 200GB HDD into his computer, set the
cache to 175GB ... and it just didn't work. I do not know exactly what the
symptoms were but if anyone is interested, I can do it again and post what
happens.

OK - back to the most interesting question: What are the theoretical and
practical limits of the cache size on linux? How do the practical limits
vary between machines accessing lots of small files and hosts accessing some
large files?

Thank you in advance for any information.

Regards,

Frank