I always had a process limitation problem on OSX. You may encounter this when you open too much applications. In my case, using iTerm, I easyily open far too much shells to servers I have to deal with.
You will then get a « login: fork: Resource temporarily unavailable » error message. When trying to start a new application, you will barely see the icon in the dock, then it will disapear. Now you’re in Troubble !

Hopefully, as OS X is a UNIX system, you have a solution. The only bad side is that you will have to reboot.

You will find a first solution if you are running Os X < 10.4 at

If you are running Leopard (10.5.x), using the first trick will lead you to the Windows Server not running… Pretty anoying. Use SSH and put back the Windowserver in its place. This is what I did, with the help of the blog at :

Sudo -s to get a root shell. Then create the two files like :

  • /etc/launchd.conf
  • cat /etc/launchd.conf
    limit maxproc 512 2048
    limit maxfiles 512 unlimited
  • /etc/sysctl.conf
  • cat /etc/sysctl.conf
    # Turn up maxproc
    # Turn up the maxproc per user
    # Remove core files

    After a reboot, your max user process will be raised to 512 :

    ulimit -a
    core file size          (blocks, -c) 0
    data seg size           (kbytes, -d) 6144
    file size               (blocks, -f) unlimited
    max locked memory       (kbytes, -l) unlimited
    max memory size         (kbytes, -m) unlimited
    open files                      (-n) 512
    pipe size            (512 bytes, -p) 1
    stack size              (kbytes, -s) 8192
    cpu time               (seconds, -t) unlimited
    max user processes              (-u) 512
    virtual memory          (kbytes, -v) unlimited