Hello, We are running Red Hat Enterprise Linux AS release 4 (Nahant Update 4) with OCFS2 for our mail servers. There are three nodes in the cluster with shared storage and OCFS2 filesystem on it. The filesystem is used for mail storage(using Maildir layout) and is accessed by smtpd, pop3 and imap processes(DOVECOT). The system works fine but when there are mailing lists the load increases dramatically. It only occurs when there are mailing lists. We have tested it in lab with good results and now in production we are having some load problems caused by dovecot?s deliver process. In lab we had sent lots of mails but always to a few accounts. It was OK. Now there are sent less mails but there are more accounts. The load increases until it reaches about 100 and only restart fixes the problem. The umounting of the OCFS2 filesystem is not possible even when all process accessing it are killed. Any suggestions? TIA Info: Three nodes. OS: Red Hat Enterprise Linux AS release 4 (Nahant Update 4) Mailbox format: Maildir SMTP daemon: Dovecot deliver + Sendmail OCFS2 version: 1.2.5-6 Kernel Version: 2.6.9-42.0.10.ELsmp Pop3 and imap daemon: Dovecot 1.0.3 -- _________________________________________________ Jon Bl?zquez Diez jblazquez at unav.es Servicios Inform?ticos https://www.unav.es/SI/ Universidad de Navarra https://www.unav.es _________________________________________________
Jon Blazquez wrote:> The system works fine but when there are mailing lists the load > increases dramatically.> Any suggestions?First thing that I would do is to reduce number of concurrent deliver processes. I have no clue how this is done with Sendmail but with Postfix one could adjust deliver process "maxproc" value in master.cf. Tomi
On Tue, 2007-10-02 at 17:46 +0200, Jon Blazquez wrote:> Hello, > We are running Red Hat Enterprise Linux AS release 4 (Nahant Update 4) > with OCFS2 for our mail servers. There are three nodes in the cluster > with shared storage and OCFS2 filesystem on it. The filesystem > is used for mail storage(using Maildir layout) and is accessed by smtpd, > pop3 and imap processes(DOVECOT). > The system works fine but when there are mailing lists the load > increases dramatically.So you mean everything works ok as long as messages are saved into only a few mailboxes, but once there comes a burst of messages to lots of different mailboxes the load increases? Is it just one node doing the writes or all 3 at the same time? If all 3, does it work better if only 1 is doing it? How long are the deliver processes running? If they're there long enough to be straced, check what syscalls are taking the longest. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://dovecot.org/pipermail/dovecot/attachments/20071006/424a0221/attachment-0002.bin>