Mandatory Consistency Check On Every Backup Plan Execution
By creating backups, a user is sure that the backed up data is possible to restore. Unfortunately, it does not always work this way. For example, if backup data on backup storage is corrupted for some reason. The occurrence of data corruption can have many reasons, ranging from technical problems with the cloud provider’s service to industrial sabotage.
The consistency check is a mechanism that prevents possible data losses. If any discrepancies are detected, a user is notified about them. There are various discrepancy reasons: some objects are missing in backup storage or there is a mismatch between object sizes or modification dates.
Once a consistency check is started, an object list is requested along with metadata from backup storage and compared to local database records.
In all cases, the user is notified about backup data damage. If a consistency check detects discrepancies, Backup for macOS executes full backup automatically.
Current generation check is mandatory, so it is performed on every backup plan execution at the beginning of the backup plan.
Possible damage in previous backup generations (full and subsequent incremental backup chains) can be also implented with a Full consistency check.
Thus, with the consistency check completed, you are aware of any possible mismatches and can make corrections in backup plans to have guaranteed valid restores.