On Tue, Jan 02, 2007 at 11:23:10AM -0600, Steven F Siirila wrote:
We are running Dovecot 1.0-rc15 on Solaris 10 and are starting to ramp up our user count and ran into a file descriptor limit:
Jan 1 19:38:54 <hostname> dovecot: IMAP(username): Newly created index file is corrupted: /home/username/.imap/foldername/dovecot.index.tmp Jan 1 19:38:54 <hostname> dovecot: IMAP(username): file mail-index.c: line 1806 (mail_index_move_to_memory): assertion failed: (index->fd == -1) Jan 1 19:38:54 <hostname> dovecot: pipe() failed: Too many open files Jan 1 19:38:54 <hostname> dovecot: Temporary failure in creating login processes, slowing down for now
We got around this by calling "ulimit -n 512" and restarting Dovecot.
We have since set this limit to "unlimited".
This got us further (upwards of 300 concurrent users), but we are now running into what appears to be a full listen queue (connections are not rejected, but rather slow in being established).
This turned out to be a result of using the default value for login_max_processes_count (128). We now have this set to 4096 in anticipation of our moving thousands more users to the server. We've also bumped login_processes_count from 3 to 32.
What I would like to know is if anyone else out there runs with large numbers of concurrent IMAP sessions via Dovecot and has run into problems. If so, did you have to up your fd limit w/ulimit? Any other issues?
Is anyone else out there running with thousands of concurrent sessions? On our older (existing) UW IMAP servers we have seen upwards of 3000 concurrent sessions.
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Steven F. Siirila Office: Lind Hall, Room 130B Internet Services E-mail: sfs@umn.edu Office of Information Technology Voice: (612) 626-0244 University of Minnesota Fax: (612) 626-7593