Adjusting ulimit -n

March 22, 2010

The first time you run IBM Lotus Domino server on a new Red Hat Enterprise Linux (RHEL) box, you get the following message:

WARNING: the maximum number of file handles (ulimit -n) allowed for Domino is 1024.
See Release Notes and set the allowable maximum to 20000.

This message is less than ideal for a couple of reasons. Firstly, it doesn’t tell you how you’re supposed to change ulimit, and secondly it hints at the wrong way of doing it.

The wrong way is to put ulimit -n 20000 into /etc/profile, or root’s .bashrc, or even the /etc/init.d script for Domino.

The right way is to edit /etc/security/limits.conf and set up limits specifically for domino (or whatever user ID you’ve chosen to run the server under). The two values recommended are set by adding two lines to the file:

domino soft nofile 20000
domino hard nofile 49152

Filed under: Domino, Linux, System administration | Comments (0)