How to Repair Permissions with Disk Utility

Repairing Permissions is a simple procedure that Mac users can complete using the Disk Utility app or through the command line. It repairs the permissions of various files on your Mac. Learn how to repair permissions on your Mac by following our guide.

Repairing permissions is a very common solution to various problems. However, it not a solution for everything. Lots of people refer to repairing permissions as the holy grail of fixing any problem on a Mac — this isn’t true. It won’t speed up your Mac magically. It also won’t fix more serious problems or any hardware-related issues.

This are many misunderstandings when it comes to repairing permissions, so we have provided an overview here of what it does, how to run repair permissions, and why you should use it.

How to Repair Permissions with Disk Utility

This procedure will repair any discrepancies found in permissions of various files and folders on your Mac. This procedure can be carried out on any drive, both internally and externally connected drives.

1. Open the Disk Utility app. This is found inside your /Applications/Utilities folder:

apps

utilities

diskutilityapp

 

2. Select the disk from the left-hand sidebar.

3. On the “First Aid” tab, click the “Repair Disk Permissions” button. The process may take a while, depending on the disk size and the number of files to repair. The speed of the drive will also affect how long the procedure takes.

When the procedure runs, you will see messages appear in the window:

Disk Utility Permissions

4. After the procedure has finished, it will display a “Permissions repair complete” message. You can then safely quit Disk Utility.

How does Disk Utility check and repair permissions?

Disk Utility knows which permissions should be on which files. Whenever apps are installed in Mac OS X, a record of the files installed for an app are kept. This record is used by Disk Utility to refer to which permissions should be on which files, to ensure there are no discrepancies with the original files. If the permissions differ, Disk Utility displays the differences and corrects them if the Repair feature was used.

 

Which files does repairing permissions affect?

Files not installed using a package installed (.pkg) are not checked because there will be no installation receipts for Disk Utility to refer back to. Files whose permissions are changed more often during normal usage are not checked.

Tip: If you remove receipts from /Library/Receipts/, the files installed by those packages cannot be verified or repaired, which is why you shouldn’t delete things from /Library/Receipts/ . See Disk Utility shows a “No Valid Packages” alert.