[Ocfs2-users] ocfs2 on mailserver lock up

[augustasg at gmail.com]

Hello,

we are running SLES9 SP3 with OCFS2 for mailsystem. There are three nodes in
the cluster with shared storage and OCFS2 filesystem on it. The filesystem
is used for mailbox storage and is accessed by smtpd ,pop3 and imap
processes. The system works fine for a few hours but locks up so that the
OCFS2 filesystem is accessed by mail system extremely slowly. It is possible
to list the contents of the filesystem or to change the directories, but
mailsystem is working slowly. Tracing smtp processes with strace showed that
mail is delivered to mailboxes but it is done in a speed of few kilobytes
per second.
This lock up happens under heavier load when the cluster is in production
use and when it happens only restart fixes the problem. The umounting of the
OCFS2 filesystem is not possible even when all process accessing it are
killed. Currently mail system cluster is not used in production so we tried
to do some tests, but we were not able to replicate the problem while
sending several thousands of messages to a single account.
The only thing that comes in mind, that the filesystem locks in the case
when a file (message) is access by smtp process and pop3 or imap process
simultaniously when the processes are running on distinct cluster nodes.
This might happen because of lack of global knowledge of localy locked files
among OCFS2 cluster nodes.
Could this be true?
And what other reasons might be there for the problem?
Any suggestions on solving the problem?

The system information follows:
OS: Suse Linux Enterprise Server 9 Service Pack 3
Mailbox format: Maildir
SMTP daemon: Postfix (postfix-2.2.6-0.1)
OCFS2 version: 1.2.1
Kernel Version: 2.6.5-7.276-smp
Pop3 and imap  daemon: Courier IMAP (courier-imap-4.1.0-1.suse910)

-- 
Augustas Gutautas
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