Shutting down your Mac
From Mac Guides
Shutting your Mac down is the safest and best way to turn it off. While sometimes unavoidable, such as in the case of a power failure, you should avoid just cutting power to your Mac while it is running. Doing so repeatedly may possibly harm the hardware. More likely is that the system could be in the middle of some task and data could be lost or, occasionally, system files could become corrupted. Macs will normally restart just fine, if more slowly, after being improperly turned off, but better safe than sorry. If a Journaled file system is used, the chance that the file system or data will be corrupted in much smaller than otherwise. The standard Panther and Tiger format is HFS+ Journaled.
You should shut your Mac down when you need to unplug it, will not be using it for a while, or want to save power. Some users will shut their Macs down every time they're finished with them; others will do so every night. Either one is a personal preference, but neither one is really necessary in typical circumstances. Putting your Mac to sleep is often the preferred method for saving power while not using your Mac.
There are a number of ways you can shut down a Mac. You can:
- Sometimes when prompted by an Installer program to restart, you will also be presented with a Shut Down option. This will sometimes happen after installing a new update from Software Update.
- Go to the Apple menu and choose "Shut Down…"
- On some Macs, press control-eject and choose "Shut Down" from the window that appears
- On some Macs, you can press the power button and choose "Shut Down" from the window that appears
You can force your Mac to shut down. You need to do this after a Kernel panic. This is also an acceptable way of shutting down your Mac if it is booted into Open Firmware, such as when using Target Disk Mode.
To force your Mac to shut down:
- On most Macs, hold the power button for five seconds to force shutdown.
- On some Macs, press control-command and the power button at the same time to force a restart, then after the Mac is finished starting up, shut it down normally.
You can set limited automatic shutdown options within Energy Saver in OS X. Under the set conditions, OS X will prompt you beforehand to save all files and prepare for a shutdown. If no user input is received, it will continue with shutdown and unsaved changes will be lost.