Some Mac users can verify the integrity of Time Machine backups before using an instant copy or backup to restore a Mac with Time Machine. This check provides an easy way to know if the stored Time Machine backup data has been modified or corrupted, and can be a very useful trick to troubleshoot in some situations.
How to check Time Machine backups on Mac OS
- Make sure that the Time Machine backup volume is connected to the Mac as usual.
- Slide the Time Machine menu from the Mac menu bar and then hold OPTION / ALT
- Choose "Check Backups" from the menu options
It may take some time to verify the backup, depending on the size of the backup as well as the speed of the Mac.
Time Machine will check the backup by comparing checksums, and alerts the user if a problem or something has been found. If the backup is fine, no problems will be reported. Checksums may not match, indicating some type of problem, corruption or modification with the Time Machine backup, and Mac OS will provide instructions to try to correct the problem. It is also possible that the backup does not have a valid check at all.
You can verify the unencrypted and encrypted backups in this wayAlthough the "Verify Time Machine" function for checking backups has been around for a long time on Mac OS X and Mac OS , it is important to note that only modern versions of Mac OS maintain a checksum record associated with each Instant backup, so if the backup was made before 10.11 or 10.12 can not be verified by comparing the checksum.
Verifying Time Machine Backups from the Command Line
From the command line users can also check the integrity of the backups by means of "tmutil", using the following command syntax:
Tmutil verifychecksums / path / to / backupThe tmutil verifychecksums approach offers the same functionality as the Time Machine menu option except through the command line.