[OpenAFS] Re: Guidelines to speed up OpenAFS?

[Andrew Deason]

On Thu, 17 Jun 2010 15:06:11 +0200
Claudio Prono <claudio.prono@atpss.net> wrote:

> I have some problems of speed with AFS. I have a Intel Xeon 3.2 Ghz
> with 1 Gb of ram, Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320
> SCSI (rev 07) and external array MSA500.

Platform and OpenAFS version of server? Of the client? What's the
connection between the server and client?

What parameters have you given to afsd and the fileserver? What cache
size on the client?

> My average speed is 8 Mb/sec on write and something similar on read.
> Is a little slow with this performances. My question is, what i can
> try to make it more fast ? Any custom optimization, or something like
> this to solve my problem?

I recall a while ago someone reporting a large performance increase by
increasing -rxpck (on the client I think, but you could try the client
and server, too). Try setting it to different values around the range
4000-10000 or higher, and see what happens. I think some of the recent
RX changes improves this so you don't need such tweaking, but others may
correct me.

And, depending on the client version, the default chunksize may not be
sane; try -chunksize 20. But not-old versions should get it right.

If you provide the output of 'rxdebug <client> 7001 -rxstats' while
you're reading or writing at a sustained 8Mbps-ish, it may indicate what
is limiting you.

-- 
Andrew Deason
adeason@sinenomine.net