[OpenAFS] clarification on client caches

Derrick J Brashear shadow@dementia.org
Mon, 6 Sep 2004 18:02:13 -0400 (EDT)

Redirected to the list.

On Mon, 6 Sep 2004, Wes Chow wrote:

>>> Once afsd is started and
>>> assuming no cache resizes, does the number of V files that exist
>>> remain constant?
>> Yes. And even if you resize the cache, it still does. File references are
>> established at afs startup. Making new ones later is "hard".
> Assuming no cache resizes, is there a maximum size for a V file and is
> it constant?  My understanding is that this maximum size is called the
> chunk size.  Is that correct?

There is a maximum (chunk) size, yes, but it is not a hard limit on the 
file size, it is enforced in software.

> If the cache is resized, then does the chunk size also resize since
> the number of V files remains constant?

No. Because remember, you have more V files than cache size/chunk size.
But yes, you can get into situations where you can't fill your cache.

> Things work fine.  If I then run "fs setcachesize 30000000", accesses
> to /afs then proceed to hang.  I can change the cache size to about
> 25000000 and it still behaves properly.  The partition the cache is on
> is 60 gigs, so it's not running out of space.  Any ideas as to why
> it's hanging?

This is basically the same question you asked before, right? I still have 
no idea. Why not start with the cache size you want?