[Linux-cluster] GFS performance of imap service (Maildir)

[Achievement Chan]

Hello,
I will change my production system to ext3 for solving the performance problem.
Actually, I have tried GFS2 in testing server and found performance
can be improved to a acceptable level (response within 2 seconds)

However, it still not stable for production system.... and I can't
wait until RHEL 5.3 release...



2008/11/13 Kadlecsik Jozsef <kadlec at sunserv.kfki.hu>:
> Hello,
>
> On Wed, 12 Nov 2008, Achievement Chan wrote:
>
>> For handling a mailbox with 10000 email, it takes 6-8 seconds for
>> waiting response from first "SELECT" command.
>> The response time is also unstable too, sometimes it takes 10-20
>> seconds for the same mailbox.
>>
>> Based some online material, i've tried to tune the gfs. But there are
>> seems no improvement.
>> e.g.
>> gfs_tool setflag inherit_jdata /home/domains
>> gfs_tool  settune /home/domains recoverd_secs 60
>> gfs_tool settune /home/domains glock_purge 50
>> gfs_tool settune /home/domains demote_secs 100
>> gfs_tool settune /home/domains scand_secs 3
>> gfs_tool settune /home/domains max_readahead 262144
>> gfs_tool settune /home/domains statfs_fast 1
>>
>> Has anyone tried to provide imap service in GFS?
>
> We have had exactly the same problems with maildir over GFS. There was no
> tuning whatsoever which helped: the fighting for the locks for every
> file in the maildir costs so much that you cannot expect better
> performance.
>
> The best is to avoid maildir and use simple mailbox format instead. We
> went (back) to mailbox and since then our users have not complained about
> performance.
>
> Best regards,
> Jozsef
> --
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