Hi, my Unraid Server has been on the fritz lately. Been experiencing lots of crashes. One time I rebooted and noticed the xfs Unmountable: wrong or no file system notice on the drive. I stopped the array and saw I could format the drive again, so I did that. Then everything was gone on it (just this one). Did I just lose this drive, can I get this data back? I should mention I do have Double Parity (x2, I know that's redundant) drives in there, that's why I thought I was safe.

A format operation updates parity to say you have an empty drive (you get a popup warning when you try to format not to use format for data recovery). The correct handling of a drive that suddenly goes unmountable would have been to attempt to repair the file system which is described here in the online documentation.

At this point your best chance of recovering the drive’s data is to use a file recovery program such as UFS Explorer on Windows. That software is not free but it does have a free option to show what it could recover so you can decide if the cost is worthwhile.

Just a thought - is the drive by any chance showing as disabled with a red ‘x’ against it. If so then you only formatted the emulated drive and the original physical disk may still have its data intact. In that case ask here for more guidance.

You are likely to get better informed feedback if you attach your system’s diagnostics (with everything in the one zip file) to your next post in this thread. It is always a good idea when asking questions to supply your diagnostics so we can see details of your system, how you have things configured, and the current syslog.

11 hours ago, yanksno1 said:

Been experiencing lots of crashes.

Probably should run a 24 hour memtest from the unraid boot menu. RAM can cause crashes. Other faulty hardware can too, like a bad PSU.

11 hours ago, yanksno1 said:

I stopped the array and saw I could format the drive again, so I did that.

You basically erased the "map" that pointed to the data. There is no way to recover this map, you will instead need to use something like UFS explorer file recovery software to see if you can recover any data. The trial is free and will show you what may be possible to save.

11 hours ago, yanksno1 said:

I should mention I do have Double Parity (x2, I know that's redundant) drives in there, that's why I thought I was safe.

Parity is not a backup. It's a real-time computation of your current drives. Anything you do to your disks, parity is updated along with it right then and there. Parity can only save you from a disk failure, not data loss/erasure/corruption.

That's what I feared. Should have asked before I reformatted it heh. Thanks for the explanation guys.