How to continue backup if source files deleted

Get help for specific problems
Posts: 1
Joined: 22 Jan 2018

Post by grwalker • 22 Jan 2018, 21:47


I am using FreeFileSync to mirror the contents of my NAS on to another set of drives. Works very well for that.

However a few days ago one of the drives (4x3TB) in the NAS had failed. Upon re-building the RAID 5 config, the RAID config became corrupt. All data lost. But i have a back up thanks to FreeFileSync.

My question is when i copy the backups back to the NAS, i want to be able to continue using FreeFileSync to mirror where it was up to prior to the RAID corruption. ie only to mirror new/deleted files. I want this for time reasons.

Is there a way to do this or do i have to do a fresh mirror all over again, which will take a lot of time

Thanks in advance

User avatar
Posts: 659
Joined: 22 Aug 2012

Post by Plerry • 14 Jan 2019, 12:46

If all data on your NAS is lost, you have to run a full backup-to-NAS mirror copy anyway.
The simplest/quickest is then to run a full copy/paste from your backup to your NAS using e.g. Windows Explorer.
You may however also use FFS and define a new, reverse (backup-to-NAS) mirror-sync that you run once.

If not all data is lost on your NAS (like your question suggests), you may use FFS to define a new, reverse (backup-to-NAS) update-sync that you run once.

After restoring your NAS data and using your NAS again, you can then incidentally, scheduled or triggered by RTS run your previous FFS NAS-to-backup sync(s).

For your reverse sync, I suggest to first run an FFS Compare and closely examine the proposed actions.
Only once you are sure the proposed actions are correct, you should run the actual sync.
Better safe than sorry ...