[Dovecot] Problems using GFS2 and clustered dovecot

[Justin McAleer]

David Craigon wrote:
> I am trying to use dovecot. I've got a GFS2 shared volume on two servers
> with dovecot running on both. On one server at a time, it works.
>
>   

Sorry to not answer your question directly, but do you have a good 
reason to be using GFS instead of NFS? We experimented with GFS last 
year (granted, not GFS2), and found its performance pretty horrible and 
its stability comically bad... had we been paying for it, however, it 
wouldn't have been funny. OCFS2 was better, but still unreliable. Lustre 
was the best we found (it worked, at least), but it required a lot of 
hardware/admin overhead. We tried other clustering filesystems as well, 
and none of them was worth the trouble.

> The test I am trying is to attach two mail programs (MUA) via IMAPS
> (Thunderbird and Evolution as it happens). I've attached one mail
> program to each IMAPS server. I am trying to move emails around in one
> program (from folder to folder), and then checking it on the other
> program. I'm testing in effect how it would work if my users log on
> twice and end up on different servers.
>
> I seem to suffer from never ending index file corruption:
>
> Apr  4 16:55:49 mailstore-b dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): Corrupted transaction log
> file
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex.log:
> end_offset (284) > current sync_offset (104) Apr  4 16:55:49 mailstore-b
> dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): broken sync positions in
> index file
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex
> Apr  4 16:55:49 mailstore-b dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): fscking index file
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex
> Apr  4 16:55:49 mailstore-b dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): Fixed index file
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex:
> log file sync pos 1,284 -> 1, 104
> Apr  4 16:55:50 mailstore-b dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): Unexpected transaction log
> desync with index
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex
> Apr  4 16:56:18 mailstore-b dovecot:
> IMAP(david at everybody-loves.craigon.co.uk): Transaction log file
> /mnt/mailstore/e/everybody-loves.craigon.co.uk/d/david/.fish/dovecot.ind
> ex.log:
> marked corrupted
>
> This happens pretty quickly. I can also get message duplication- if I
> move a message from one server to another, I can get a message in the
> original folder and the destination folder.
>
> I am using RC28. I have tried using fcntl locking and dotlocking with
> equal lack of success. 
>
> Can anyone offer any advice?
>
> David
>
>  
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