I wanted to remove a 3 TB drive from my array. I moved all the data off and verified with Krusader that there was nothing left in the root. I wanted to use the script that zeros a drive while maintaining parity, but it failed. It took only a few seconds and the drive page then said it only had 16 gb of space. Obviously, this didn't zero anything.

At this point, I figured I would have to go with the second way of making a new config and re-syncing parity. All the drives up to this point are working fine and recognized in the system as they should be. I go to create a new config while saving the assignments then remove the 3 tb drive that now has nothing on it. Since it's a new config, all the drives say auto filesystem before the array comes online. This is normal I think. So I start up the array expecting to have to let it rebuild parity and such which takes about 24 hours as my largest drive is 10tb. I am, however, greeted with only 4 out of 8 drives (and the cache pool) recognized as mountable partitions. The rest say auto and unrecognized or unmountable partition.

I immediately start sweating at this point and stop the array as I don't want the system to be reading/writing from it in this state until I understand more of what's going on.

I figure that the worst case is I can use some file recovery on my PC to get the files off which would be an incredibly lengthy process since it's like 11 tb of data across all drives. Since parity isn't valid anyway, I could use my parity drive to hold the data, reformat, the recopy it without protection before rebuilding parity.

But first I figured I would try some easier solutions. My main computer is a Windows machine which obviously doesn't recognize XFS. First I tried Linux file systems for Windows by Paragon software. It didn't recognize any drive that was already recognized by unraid nor any of the ones that weren't. Second was Hetmann Partition Recovery which immediately recognized everything. So this told me the drives/file systems must be at least mostly intact. I quickly downloaded ubuntu and stuck it in a vm then passed through one of the drives that Unraid didn't recognize, and it had no problem mounting it.

I ran xfs_repair on one of the drives just to see if there was some file system corruption causing the issue, but it still isn't recognized by Unraid despite the local xfs_repair tool understanding the drives (or at least the one drive I'm using for testing). Unnassigned Devices also has mount greyed out.

Anyone have any other ideas? Preferably ones that don't involve me copying the data from the drives, reformatting them, the copying the data back since that would be unprotected.

EDIT: So I realized I could just force the system to look at the drives as xfs when the array was unmounted. I'm not sure why it didn't just recognize this fact for all drives immediately without me having to do this, but it did ultimately work. Or at least, it's currently syncing parity and in 24 hours it will hopefully be fine.

What I did in case anyone finds this threat later, was just set everything to xfs from auto then started in maintenance. Then I ran the xfs_check from each disk page to confirm the system didn't think there were any file system corruption (there wasn't). Then when I started the array... everything broke for an unrelated reason. But when I fixed that problem, it all worked fine.

The unrelated issue had to do with one of my cache drives that randomly disconnected for some reason which caused a lot of kernel errors and the system freaked out and crashed.

Edited August 15, 2025Aug 15 by cloaknsmoke
fixed problem maybe

5 hours ago, cloaknsmoke said:

EDIT: So I realized I could just force the system to look at the drives as xfs when the array was unmounted.

This suggests the drives have multiple fs signatures, if you want to fix that once and for all, stop the array and post the output from:

wipefs /dev/sdX1

for one of the affected drives.

That's an interesting hypothesis. 3 of the 4 drives did come from a Windows PC previously and therefore have had multiple filesystems over the years. However, 1 of them has only been used on my Unraid computer. It was a parity drive first. I may have formatted it as ZFS at some point before deciding that it was screwing with the performance and formatting to XFS. I'll try this out tomorrow once the parity sync is done.