changing open files system limitations for the use of mongodb

This is done in by modifying the lauchd configuration. You can set the maximum number of open files by running the following command in the Terminal:

sudo launchctl limit maxfiles SOFTLIMIT HARDLIMIT

Change the soft limit and hard limit numbers accordingly, or use "unlimited" to specify no limit.

Try this with your current setup, and if you find a value that works for your needs then you can create a launchd configuration file in /etc/ by running the following command:

sudo pico /etc/launchd.conf

In the editor, place the following as a single line in the file:

limit maxfiles SOFTLIMIT HARDLIMIT

...then press Control-O to save, and Control-X to exit, and then reboot to have this value be used.

The default value of "256 unlimited" is the recommended value for this setting, but if you're running into limits with your database then try doubling it until you get to a value that works.

As a precaution, be sure to keep the hard limit set to "unlimited" and only adjust the soft limit. To do this you will need to specify both values. If you use just one value then I believe both will be set to this value, and you can freeze your system if you do so.

You also might just use the "sudo" command I mentioned above to test the setup, before you apply it to any configuration files. This will ensure if you do experience a crash or hang, that it will revert when you restart your computer.

Try using double whatever the soft limit is, so if you're using 1024 then use 2048 for the hard limit.