RHEL4 Sun Java Messaging Server deadlock

[John Dalbec]

Sun Java(tm) System Messaging Server 6.2-9.20 (built Jul 15 2010)
libimta.so 6.2-9.20 (built 01:27:24, Jul 15 2010)
Linux myysumail.ysu.edu 2.6.9-89.31.1.ELhugemem #1 SMP Mon Oct 4 
22:04:11 EDT 2010 i686 i686 i386 GNU/Linux

The IMAPd process appears to get into a deadlock with pdflush and 
kjournald.  The mailboxes were initially stored on a disk partition but 
I'm in the process of migrating them to a LVM logical partition.  Both 
partitions are ext3.  I worry about using ext2 because a fsck takes 
about 90 minutes.

The server has 32GB RAM.  Right now Committed_AS is around 4GB, but the 
system is lightly loaded.  I'm running a 32-bit kernel because the 
application vendor doesn't support 64-bit.

I can't upgrade to RHEL5 because the application vendor doesn't support 
it.  When the deadlock happens it affects parts of /proc.  If I run "ps 
ax" the "ps" process enters an uninterruptible wait and stays there.  I 
have to power-cycle the system to return to normal operation.

What are my options?  I have SELinux enforcing.  Should I disable it?  I 
have vm.overcommit_memory = 1.  Should I set that to 0 or 2?  Do I have 
to fall back to ext2?

Thanks,
John Dalbec
SunGard HE Luminis 4 system administrator
Youngstown State University