Quick Guide: How to Repair Disk Permissions in OS X

Lego figure working on a computer hard drive

One huge plus to having a Mac is never having to defrag your computer. Apple computers seem to run without issue ad infinitum, which, as Martha Stewart would say, is a very good thing.

The key word there, though, is SEEM. While your Mac might not scream out like a PC when it’s time to defrag, it still needs a little TLC from time to time.

The most common task is Repair Disk Permissions. Completing this bit of routine maintenance is pretty simple, and while you won’t get the system-wide repair that you get when doing a defrag on a PC, there are still some great reasons to make this part of your routine maintenance work.

Before getting into how to repair disk permissions, it’s worthwhile to see why completing this task is helpful.

RELATED: 7 Tips to Make OS X Run Faster

Why Repair Disk Permissions?

In short, repairing disk permissions is the act of reassigning the permissions of files and folders to be what they should be. There’s a lot involved here, but for the sake of brevity, all you need to understand is that sometimes permissions such as the ability to read and write to folders get fouled up. This can be due to installing and uninstalling applications, or moving from one drive to another. Whatever the case, it happens. And when permissions don’t line up, applications don’t work as expected.

Depending on how severe your permission issues are, this can even affect how OS X runs. Repairing disk permissions won’t do a lot to speed up your Mac, but it will make files save correctly and keep apps from crashing.

Now that you have an idea what we’re talking about, let’s look at how to repair disk permissions.

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How to Repair Disk Permissions in OS X

The great thing about learning how to repair disk permissions is that it really hasn’t changed since OS X has been around. While Macs have gotten better at not damaging permissions, how you repair them has remained unchanged.

First, head to Applications, open the Utilities folder, and double-click on Disk Utility.

Disk Utility highlighted in Utilities window

From here, click on the partition you want to repair. Make sure you click the partition and not the drive, as you can only repair permissions for partitions. With the disk partition selected, click Verify Disk Permissions.

Verifying permissions for a partition in Disk Utility

The tool will now verify that all permissions on your drive are what they should be, and list any inconsistencies in the detail window. Since this takes less time than a full repair, it’s worth checking your drive first. If you find some errors, then it’s on to Step 2.

Permissions errors displayed in Disk Utility window

If your window looks like the one above, you have some permissions errors and you should repair them.

To repair disk permissions, just click – you guessed it – Repair Disk Permissions. Depending on how many issues you have, this can take anywhere from 1 to 20 minutes. Usually it’s around 5 to 10 minutes.

When your Mac is done, you should see the message “Permissions repair complete” at the bottom of the window. When this comes up it means you’re all done. If you have multiple drives or partitions, you should complete this process for each of them. Don’t bother trying to run this on a Bootcamp partition – OS X won’t even try it.

Once you’ve done this to all your drive partitions, you’re all set. No restart is required. Just start using your applications and see if you notice a difference.

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