The Backup Health Monitor feature introduced in build 7.1.5 and onwards will run in the background and detect any integrity issues with your backup data due to disk issues.

If issues are found the Monitor will attempt to resolve the issues automatically by backing up the affected data again during the next backup. Any issues detected which weren’t automatically resolved are reported in the Altaro VM Backup Management Console showing which Virtual Machine Backup Versions cannot be restored.

Obviously, if you are notified regarding any bad blocks on your backup location, do run some diagnostic checks and check relevant logging too.

You have a couple of configuration options that allow to you select the number of days you wish to verify (which goes up to all versions).

Besides that you also have the option to allow the health monitor to run only during the specified time frame you give it. When it falls outside of that time frame it will pause the check and resume when it's allowed to run.