What does Repair Disk Permissions do?
Every file, folder, and application on your hard drive has associated permissions that specify which users can read, write, or run that file. For example, you can set up your computer so that your cat can’t delete your dog’s files. These complex permissions can become confused or corrupt, and even administrators can be prevented from opening applications.
When your system was first installed, and every time you install an application or update through an Apple Installer, a receipt is left on your system. This receipt (in Macintosh HD/Library/Receipts) lists what files were installed, where, and what the permissions were supposed to be. Programs that were installed by dragging the application directly to the Applications folder or using a non-Apple installer, do not leave receipts.
The Repair Disk Permissions function reads all these receipts, and attempts to reset the files on your disk to match their state at installation. This can be quite useful.
Here's how to repair your disk permissions on your Mac. While booted from your normal startup drive, open Disk Utility (in the Utilities folder, in the Applications folder). Click the name of your startup disk, and click Repair Disk Permissions.
Published March 24, 2009 12:00 PM
Last modified on June 15, 2009 3:29 PM
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