[Dovecot] Another "Too many files open" post

Jeff A. Earickson jaearick at colby.edu
Wed Dec 21 15:29:23 EET 2005

    This sounds like a kernel parameter issue, not a dovecot.conf
twiddle.  My system supports 3000 users, and "ulimit -a" has no
mention of "open files" at all.  With maildir format, you would
have a lot of open files (I use mbox).

My /etc/system has the following additions, which I put in when
I first started using alpha3:

* double file descriptor limits for dovecot
set rlim_fd_cur = 65536
set rlim_fd_max = 131072

I don't have any ulimit or plimit twiddles in my startup script, as
others have suggested.  Per their advice, use plimit or adb to
adjust things until you can change /etc/system and reboot.

Jeff Earickson
Colby College

On Tue, 20 Dec 2005, Andy Cravens wrote:

> Date: Tue, 20 Dec 2005 16:59:08 -0700
> From: Andy Cravens <acravens at uen.org>
> To: dovecot at dovecot.org
> Subject: [Dovecot] Another "Too many files open" post
> I'm running Solaris 9 Sparc with Dovecot alpha 5 and using maildir format.. 
> I noticed in the log file the following error:
> dovecot: Dec 20 15:54:18 Error: imap(xxxxxxxx): 
> open(/export/home/xxxxxxxx/mail/.Sent 
> Messages/cur/1135013649.002916.mbox:2,Sab) failed: Too many open files
> I called the guy and asked him what he was doing... synching his folders.  It 
> hung for a while but finally finished.
> I searched the archives and found some related info from Jeff Ballard:
>> Actually on Solaris 9 you want to put something like this in >/etc/system:
>> set rlim_fd_cur = 32768
>> set rlim_fd_max = 65536
>> That sets the current fd's to 32k and max to 64k.  Unfortunately, to >take 
> effect you'll need to reboot.  After the reboot, ulimit -a should >show that 
> nofiles(descriptors) is 32768.
>> -Jeff
> And I found this from Jeff Earickson:
>> I ran into this problem with alpha4 on Solaris 9.  I doubled the
>> following dovecot settings:
>> login_max_processes_count = 256 (was 128)
>> login_max_logging_users = 512 (was 256)
>> and the problem went away.  I carried these numbers forward intoalpha5,
>> and it has been working fine.
> I changed my /etc/system file but have not rebooted yet.  Also, on Jeff 
> Earickson's post, I looked at my dovecot.conf settings and they're basically 
> default which means everything in the "Login processes" section is commented 
> out.
> I have 10 users on this system and will hold off migrating any more until I 
> can resolve this problem.  By the way, my "ulimit -a" shows "open files" at 
> 256 which seems low.
> # ulimit -a
> core file size (blocks)     0
> data seg size (kbytes)      unlimited
> file size (blocks)          unlimited
> open files                  256
> pipe size (512 bytes)       10
> stack size (kbytes)         8192
> cpu time (seconds)          unlimited
> max user processes          29995
> virtual memory (kbytes)     unlimited
> Any advice would be appreciated.  I can't reboot for a few more days.

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