[Ocfs2-users] Really high io wait times with OCFS2 in a mail server

[Isaac Clerencia]

Hi there.

We have just setup a mail server with storage in a EMC Clariion SAN with 
fiberchannel connections.

We're using two HP Proliant servers sharing the mail filesystem with OCFS2.

The mail filesystem has several big directories having the biggest one over 
7000 user directories.

Some of the users have over 4000 messages, using Maildir as mail layout.

We are experiencing really high IO wait times (up to 90% of CPU time 
sometimes) and sometimes several mail processes (POP and IMAP daemons) get 
stalled for several seconds (or up to a minute in the worst cases) waiting 
for disk IO.

We're not sure if there is a way to fix this. Would adding an extra computer 
help? Would adding an extra fiberchannel card in the hosts and using 
multipath help? Any other idea?

Best regards