[OpenAFS] Re: Expected performance

Andrew Deason adeason@sinenomine.net
Thu, 19 May 2011 13:25:20 -0500

On Tue, 17 May 2011 23:14:03 +0100
Hugo Monteiro <hugo.monteiro@fct.unl.pt> wrote:

> - Low performance and high discrepancy between test results
> Transfer rates (only a few) hardly touched 30MB/s between the server and 
> a client sitting on the same network, connected via GB ethernet. Most of 
> the times that transfer rate is around 20MB/s, falling down to 13 or 
> 14MB/s in some cases.

The client and server configs would help. I'm not used to looking at
single-client performance, but... assuming you're using a disk cache,
keep in mind the data is written twice: once to the cache and once on
the server. So, especially when you're running the client and server on
the same machine, there's no way you're going to reach the theoretical
110M/s of the disk.

You may want to see what you get with memcache (or if you want to try a
1.6 client, cache bypass) and a higher chunksize. Just running dd on a
box I have, running a 1.4 afsd with -memcache -chunksize 24 made it jump
from the low 20s to high 40s/low 50s (M/s), after starting with the
defaults for a 100M disk cache.

Andrew Deason