[BlueOnyx:12151] Dovecot Error: socketpair() failed: Too many open files

[David Thacker]

Greetings,

Twice in the past week (but never previously) I've had a problem on my 
BX5107 server where Dovecot stops accepting many (but not all) imap and 
pop3 logins. It seems that many real users and Active Monitor can log in 
fine.

The error reported in maillog is:

    Error: socketpair() failed: Too many open files

If I do "service dovecot restart" then the problem is resolved. 
Unfortunately with Active Monitor not detecting the problem, it is usually 
a mail user that brings this to my attention.

I googled around a bit and saw this post which seems relevant:

http://hans.rakers.org/2011/05/dovecot-and-the-too-many-open-files-error/

So, to try to prevent this in the future I made the recommended change to 
/etc/sysconfig/dovecot which is to add this option (there were no other 
options in the file previously):

# DT 2013-02-04 prevent too many open files error for email logins
# Increase max open files for dovecot process
ulimit -n 4096

I restarted Dovecot again after making this change, and so far so good.


Questions:

1. Are there any known problems making this config change, or any known 
better solutions?

2. Will this change get overwritten when Dovecot is YUM updated or by any 
other automatic updates?


Thanks!

David Thacker