How to verify or test a bootable backup

Attach the backup disk to your computer

Open the Startup Disk Preferences

System Preferences > Startup Disk

Select the backup volume

After clicking the lock in the lower-left corner, select the backup volume that you would like to verify. Click Restart.

If you do not see your startup disk here, reboot your Mac while holding down the Option key (Intel Macs) or the Power button (Apple Silicon Macs) to choose the startup volume in the Startup Manager.

Some Big Sur startup volumes don't appear in the Startup Disk Preference Pane

Verify the startup disk

When your Mac has finished restarting, choose About this Mac... from the Apple menu.

Verify that you are booted from the backup volume.

Test the Backup

Launch a few applications and verify that your data is intact.

Reset the Startup Disk

Reset your startup disk in the Startup Disk preference pane (as described earlier) to your original startup disk, then restart your computer.

Related Documentation

For a more in-depth verification of the integrity of your backup, see the Advanced Settings article to learn more about the Find and replace corrupted files option.

• Some applications behave differently or ask for the serial number on the cloned volume. Did CCC miss something?"
• "The disk usage on the destination doesn't match the source — did CCC miss some files?"
• Help! My clone won't boot!