[OpenAFS] openafs on Fedora 12?

Simon Wilkinson sxw@inf.ed.ac.uk
Fri, 11 Dec 2009 17:30:28 +0000

On 11 Dec 2009, at 12:56, Chas Williams (CONTRACTOR) wrote:

> In message <4B220A1A.8080001@pclella.cern.ch>,Rainer Toebbicke writes:
>> With the current "dir" package this means a chunk size of 2MB.  
>> Assuming the
>> unit of transfer is still "chunksize" and you do not intentionally  
>> fill chunks
>> partially you'd give up a valuable tuning parameter.
> hmm... well it is a future problem.  i would actually suggest 1MB  
> chunks
> for a disk cache anyway.  the directory problem is interesting.   
> perhaps
> afs should be able to handle partial dir chunks.  i would have to look
> into this.

The main issue with handling partial directory chunks would be that  
the dir package currently gets passed a single dcache, rather than the  
vcache of the directory - so it doesn't currently have any way of  
accessing other chunks beyond the one that its passed. Changing that  
shouldn't be that difficult in theory - if anything causes pain, I  
would imagine it will be the lock hierarchy.

If and when we do extended directories, the directory size is going to  
get much larger (you're storing 3 of everything, for a start) so we'll  
probably need to address this at some point.