


Step 4.Force Mount Your Hard Drive in Disk Utility.Step 3.Make Sure Your External Disks are Visible.Scanning and Recovering Files From Your Byte-By-Byte Backup Step 1. Using Disk Drill to Backup Corrupted Hard Drive Data.Fixing Corrupted External Hard Drives On a Mac.Signs of a Corrupted Internal Hard Drive.Signs of a Corrupted External Hard Drive.Add in the fact that there are TWO TM backup systems on the drive, plus whatever FreeFileSync tried to write and the probability of successful recovery goes down. Maybe somebody else can help with that particular factor. I've never tried a recovery tool on a TM backup drive, and have no idea if anything can be done. Tools that recover hard drives may not know the difference between files and links. In a lot of cases that will be the first backup on the drive. What TM puts on the drive are not really files, for the most part, but links to files, in chains, from backup to backup until you get to the last time the file changed. But I'm not really that optimistic on that because of the TM backups.


You can also look at some of the third party recovery tools, also not inexpensive, to see if any of them can recover your data. There are professional services that may be able to rescue your data, but it will be expensive. However, I suspect that the failed mirroring process may well have damaged the "directory" structure of the drive to the point where it can't be fixed short of a reformat. They do claim it works, and from some of the posts in the forum there, it does seem to work with macOS. I think you meant FreeFileSync, not FeeFileSync, so I did some reading at their website.
