[Linux-cluster] GFS RG size (and tuning)

Jos Vos jos at xos.nl
Fri Nov 2 20:33:09 UTC 2007


On Fri, Nov 02, 2007 at 04:12:39PM -0400, Wendy Cheng wrote:

> Also I read your previous mailing list post with "df" issue - didn't 
> have time to comment. Note that both RHEL 4.6 and RHEL 5.1 will have a 
> "fast_statfs" tunable that is specifically added to speed up the "df" 
> command. Give it a try. If it works well, we'll switch it from a tunable 
> to default (so people don't have to suffer from GFS1's df command so much).

OK, thanks, we'll try with 5.1.

In the meantime we rebuilded all fs's with larger RGs (-r 2048), which
already improved the "df" behavior seriously.

Also, fs performance is not that bad w.r.t. bandwidth (our measurements 
were first incorrect due to 32-bit counter troubles), but operations like
rsync (which we do a lot) that scan large directory trees are horrable.
For that we'll wait for 5.1.

-- 
--    Jos Vos <jos at xos.nl>
--    X/OS Experts in Open Systems BV   |   Phone: +31 20 6938364
--    Amsterdam, The Netherlands        |     Fax: +31 20 6948204




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