[Linux-cluster] GFS tuning advice sought

[Gordan Bobic]

> James Fidell wrote:
> 
>> I have a 3-node cluster built on CentOS 5.1, fully updated, providing
>> Maildir mail spool filesystems to dovecot-based IMAP servers.  As it
>> stands GFS is in its default configuration -- no tuning has been done
>> so far.
>>
>> Mostly, it's working fine.  Unfortunately we do have a few people with
>> tens of thousands of emails in single mailboxes who are seeing fairly
>> significant performance problems when fetching their email and in this
>> instance "make your mailbox smaller" isn't an acceptable solution :(
>>
>> Is there any GFS tuning I can do which might help speed up access to
>> these mailboxes?

I have implemented similar mail systems in the past, and I hate to tell 
you this, but if you really have tens of thousands of emails in a single 
folder and you need to sift through them frequently, even a 
single-user-server with ext3 won't give you any kind of a sane 
performance over a WAN. Even on a 100Mb LAN, things will end up timing 
out, even without clustering.

You'll have to split the huge mail folders up into several smaller folders.

Gordan