Red Hat Enterprise Linux Troubleshooting Guide

Changing user limits

Since we suspect the open files limit is preventing the application from executing, we can set its limit to a higher value. However, this is not as simple as executing ulimit –n; the following output is what we get when it's executed:

$ ulimit -n
1024
$ ulimit -n 5000
-bash: ulimit: open files: cannot modify limit: Operation not permitted
$ ulimit -n 4096
$ ulimit -n
4096

By default, on our example system the highest the vagrant user is allowed to raise the open files limitation to is 4096. As we can see from the preceding error, anything higher is denied; but like most things with Linux we can change this.

The limits.conf file

The user limits that we have been using and modifying are part of Linux's PAM system. PAM or Pluggable ...