[Linux-cluster] Performance tuning help sought

[Kadlecsik Jozsef]

On Wed, 5 Mar 2008, Kadlecsik Jozsef wrote:

> Digging into the mailing list archive brought out some GFS tuning options 
> too. What is already done:
> 
> - statfs_slots set to 128
> - statfs_fast set to 1	
> 
> What we are going to try is to set 
> 
> - glock_purge to 50
> - demote_secs to 150

The new settings did not really help, unfortunately.

I believe our performance problem might come from bouncing locks: there is 
no way to deliver incoming mail systematically to the same machine where 
the user is actually logged in or connected to via POP/IMAP. So when we 
see bad performance that may be the result of delivering to one machine 
and accessing the mailbox from another one.

Which knobs should we tune in order to achieve the fastest lock 
processing?

Also, currently we use maildirs. Were mailbox format better suited to GFS,
from locking point of view?

Best regards,
Jozsef
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