Disk Utility 12.x: Verify a disk
You can check a disk for problems without repairing it. If you used the disk to start up your Mac, verifying means you don’t need to restart your computer unless you need to repair your disk.
As Disk Utility checks a disk for problems, your computer may become slow or unresponsive.
- Open Disk Utility, in the Utilities folder in Launchpad.
- Select your disk and click First Aid.
It’s best to select the disk, which is at the far left, and not a partition on a disk, which is indented to the right under the disk. If you select the disk, Disk Utility checks all partitions on that disk and performs some additional disk-wide checks. If you select a partition, Disk Utility checks only the partition you selected.
- If Disk Utility tells you the disk or partition is about to fail, back it up and replace it. You can’t repair it.
- Click Verify Disk.
If Disk Utility reports that it appears to be OK, you’re done. Otherwise, you need to repair it.