[OpenAFS] Performance issue with "many" volumes in a single /vicep?

Steve Simmons scs@umich.edu
Wed, 24 Mar 2010 16:34:36 -0400


On Mar 18, 2010, at 6:43 AM, Jeffrey Altman wrote:

> In the 1.4 series, the volume hash table size is just 128 which
> would produce (assuming even distributions) average hash chains of
> 160 to 220 volumes per bucket given the number of volumes you
> describe.  This is quite long.
> 
> In the 1.5 series, the volume hash table size defaults to 256
> which would be an average hash bucket chain length of 80 to 108.
> 
> I would say that for the number of volumes that you are using
> that you would want the hash table to be no smaller than 4096
> which would bring the average hash chain length below 7 per bucket.

Dan Hyde is trying this out now.

Steve