Hi all,

I’m looking for help or at least a sanity check. Here's what happened:

• I had a single-drive BTRFS cache pool in Unraid (originally one drive, later expanded).

• My VM disks were stored in the domains share, and unbeknownst to me, everything was actually living on the cache, not the array — even though the share was set to use the array as primary storage.

• I went to add a second drive to the pool and, in the process, formatted the cache pool via the GUI — thinking the important data had already been offloaded to the array.

• After the format, the new BTRFS pool (1TB + 2TB) was created, and the old data vanished.

What I’ve tried:

• TestDisk: Found the old BTRFS partition but couldn’t list files (no BTRFS support in the build).

• btrfs restore: Detected internal trees but no usable subvolumes or files.

• I removed the drive and scanned it on Windows using PhotoRec.

• It’s currently recovering thousands of files — mostly false positives like .exe, .txt, .png, etc. — no .img or .qcow2 files yet.

My Questions:

1. Has anyone else been in this situation and actually recovered VM disk images from a formatted cache drive?

2. If you did recover them, what tools or methods worked for you — was it PhotoRec, ddrescue, something else?

3. Any chance that .img or .qcow2 files might be hiding under misidentified file types in PhotoRec?

At this point, I'm just hoping someone has walked this road and found a way back. I know BTRFS makes this trickier — especially with overwritten superblocks — but if there's anything else I should be trying, I’m all ears.

Thanks in advance.

If you have formatted a Btrfs partition, it is advisable to stop using the disks immediately and attempt recovery as soon as possible to avoid overwriting the deleted data.

while possible to recover some data from, formatted drives. IT can be a long and tedious and expensive data to get specialized hardware and software to recover files.

No, I'm not aware of anyone in the public sector restoring data from formatted disks.

Using btrfs-restore, you can attempt to recover files by specifying the device and the mount point where you want to restore the files. However, the success rate of manual restoration can be uncertain and requires technical knowledge...

https://man7.org/linux/man-pages/man8/btrfs-restore.8.html

Possible yes, but the data should be considered lost at this time... from my college disk forensic and security college class. I can't in good census assist with format disk recover, and the processes takes a long time if at all of any data is recoverable...

https://www.youtube.com/watch?v=hmpY8TlBck4

https://unix.stackexchange.com/questions/168704/data-recovery-from-an-accidental-format-on-ext4-partition

I would take the VM loss and start over.

You can try a file recovery app like UFS explorer, they have a free trial that should show what it can recover.