Aaron Adams’s Blowhard Blog

Every now and again, Mac users may have a reason to perform certain file system maintenance tasks. Mac OS X, like most operating systems, cannot perform those tasks while the system volume is mounted. This means the machine has to booted into single user mode by holding down command-S during the Mac startup chime and running these maintenance utilities from the command line.

Wouldn’t it be nice if someone wrote a script to automate such things for the Unix impaired? They have, and it’s named AppleJack.

AppleJack installs a shell script that is immediately available upon booting into single user mode. Simply type “applejack” at the prompt and you’ll be presented with several repair options including file system check, repair permissions, preference validation, cache clearing, and swap file removal. If you wish to perform the full regimen of maintenance tasks, you can select them in order from the menu or select the “auto” option and each one will be done sequentially. Reboot at the end and your Mac’s file system is healthy and ready to go.