Lately I was starting my demo environment to update my virtual machines. I had installed a new SCCM 2012 R2 server and wanted to migrate all agents.

I discovered a problem when I was starting the 35th virtual machine on Fusion 6.0.3.

The message stated “Too many open files” and Fusion crashed after I clicked ok.

Problem_Report_for_VMware_Fusion 2

After some googling I found out that there is a hard limit on Mac OS Xs 10.9.3 amount of open files.

To check that limit start the terminal and insert the following command:

launchctl limit maxfiles

That returned me:

Maxfiles 256 unlimited

Now I wanted to increase the open files limit with:
sudo launchctl limit maxfiles 9000 unlimited

That returned me:

WARNING: Improper use of the sudo command could lead to data loss
or the deletion of important system files. Please double-check your
typing when using sudo. Type “man sudo” for more information.

To proceed, enter your password, or type Ctrl-C to abort.

Neither the hard nor soft limit for “maxfiles” can be unlimited. Please use a numeric parameter for both.

Then I tried:

sudo launchctl limit maxfiles 9000 65536

But sadly that doesn´t solve the problem because the change is only for the specific terminal session.

Googeling again….

Ok, we need to add the line “limit maxfiles 9000 unlimited” to etc/launchd.conf which was not present on my system.

This did the trick and now 51 machines are running without any problems.