Before you back up your startup disk, make sure the destination disk has no errors that could prevent a reliable backup from being made.
Verify the Destination Drive
- Launch Disk Utility, located at /Applications/Utilities/.
- Select the destination drive from the device list in Disk Utility.
- Select the 'First Aid' tab in Disk Utility.
- Click the 'Verify Disk' button.
The disk verification process will begin. After a few minutes, the following message should appear: “The volume {volume name} appears to be OK.” If you see this message, you can go on to the next step.
Verification Errors
If Disk Utility lists any errors, you will need to repair the disk before proceeding.- Select the destination drive from the device list in Disk Utility.
- Select the 'First Aid' tab in Disk Utility.
- Click the 'Repair Disk' button.
The disk repair process will begin. After a few minutes, the following message should appear: “The volume {volume name} has been repaired.” If you see this message, you can go on to the next step.
If there are errors listed after the repair has finished, repeat the steps listed above under Verification Errors. Disk Utility can sometimes only repair a few types of errors in a single pass, so it may take multiple passes before you get the all clear message, letting you know that repairs are complete, with no remaining errors.
