Unfreeze a Frozen Mac over the Network

Task #96

Difficulty Level 4

Even with the power of UNIX behind them, computers can still sometimes act up. When an application crashes or hangs, you can force it to quit by pressing z+Option+Escape or by Option+clicking its icon in the dock. However, sometimes even these strategies will not “thaw” a frozen Mac. Using the Terminal application via another computer on the network, though, you can log in to the offending machine and manually stop whatever is freezing your Mac.

The easiest way to remotely connect to another Mac on a network is to use a tool called ssh. It permits you to connect to another machine and issue it commands as if you were actually sitting in front of the machine. The ssh tool operates in a secure fashion, so you can be reasonably certain that other users on the network will not be able to “watch” your activities as you work.

Put It Together

Before you can unfreeze a computer over the network, you must first activate Remote Login in the Sharing pane of System Preferences; see task #92 for more information. Use safe networking practices when activating the powerful Remote Login features in Panther.

Caution

You should be very careful when you use the kill command. Killing the wrong process can have an adverse effect on the operation of your Mac. If you manage to screw things up beyond hope, you can always restart the frozen Mac.