Disk Utility Notes: February 13, 2010 at Shalom Retreat Center

Apple’s Disk Utility program includes a function called Disk First Aid. Disk First Aid handles two tasks: Repairing Permissions, and Repairing directory files on the hard drive. One should repair permissions weekly, usually right before running Software Update.

The Repair Permissions task checks and repairs permissions in only Apple originated installer packages. These permissions files may need repair if Apple programmers got something wrong. Or, the permissions for an Apple originated program may have been modified by a third-party installer. In general whenever an Apple originated program tells you that you can’t don’t have the authority to do something today that you could do yesterday, repair permissions.
For best results run repair permissions from the copy of Disk First Aid on your hard drive while you are started up from the hard drive. For example, don’t run the repair permissions from the OS X install CD while started up from the install CD that came with your computer.

Disk First Aid can verify the condition of the hard drive without starting up from another volume. This feature is called Live Verification. In the picture above the Verify Disk button is active for Live Verification. Do Disk First Aid’s Live Verification once a month.

If problems are found, no repairs can be made until you start up from another volume containing a copy of Disk Utilities. By another volume, I mean the OS X install disk, or another partition of the hard drive, or an external drive.

In the above picture the Repair Disk button is active.

What happens when Disk First Aid finds a problem with the hard drive that it can’t repair? Apple says if DFA can’t repair the drive, erase the drive and restore from backups. We say it’s time for Disk Warrior. Alsoft’s Disk Warrior will help you recover files when you experience bad directory errors. Disk Warrior doesn’t just patch the directory it creates a new directory. It is a one trick pony, but it does its trick very well. Does everybody need to own Disk Warrior? No, but they need to know someone who owns Disk Warrior. The program runs from its CD. Start up the ailing computer from the CD and let Disk Warrior do its thing.

Pricing for Disk Utility: free with a Mac. Disk Warrior is $99.95