Hello Everyone,

I was trying to increase my storage and at the same time modify a few old file format disks (reiserFS to XFS). At first, I thought that pulling out a disk (stopping aray, unmounting, turning off, removing disk, adding new disk, replacing) would do the trick. About 2% into rebuilding the disk I realized I hadn't canged the format, that it was rebuilding in ReiserFS. I stopped the rebuild, changed the format, and started it again. This is the point I think I screwed it up. I noticed my "capacity" went from 85% of my total to 70%. This morning I tried to put the old drive back in, it warned me that putting in the disk would erase it. Is there any way I can fix this issue? I'm trying to get back to where I was yesterday with this older drive (I never modified this original drive) in the array, then I can figure out the correct way to move forward since I seem to have screwed it up.

Thanks!

I can get into the server, see the disk, and right now the whole array is offline. It won't let me select ReiserFS since it's deprecated. This drive has not been formatted however, only the new one I Was attempting to replace it with. Not sure if this helps or not. I am in a bit of a panic over this afraid that I lost 15% of everything in my array..

You cannot format a disk to change the filesystem while keeping the data, but if you still have the old disk, you can mount it with the Unassigned Devices and copy the data to the new one.

1 minute ago, JorgeB said:

You cannot format a disk to change the filesystem while keeping the data, but if you still have the old disk, you can mount it with the Unassigned Devices and copy the data to the new one.

I do have the old one, but I don’t have space in the array to add a new blank 8TB one (the one I was trying to add and format). There is no way to revert to add the unmodified disk back into the array (before I formatted the new disk) and then copy off the data and do the process correctly since I clearly screwed it up?

Right now I can see the old drive (hooked up via USB) and the array is rebuilding with the new one on XFS. Is there a guide or some tips on how I can move the data from the old drive to the new one once the rebuild is complete?

You can mount it with the Unassigned Devices plugin and then use the File Manager or your favorite tool to copy the data from that disk to the array.

4 minutes ago, JorgeB said:

You can mount it with the Unassigned Devices plugin and then use the File Manager or your favorite tool to copy the data from that disk to the array.

So basically, in order to fix the old file system on some of my disks, I would have needed to do something similar to this anyways? Makes me feel a little better about all this lol.

If you have space on the array, you can also use the mover to empty an array disk, format it with the new filesystem, then move on to the next one

I may try to do that with the remaining ones. Thanks so much for the help, I really appreciate it!

So I have the drive in an external USB reader and hooked up, I can see the drive name/info, but when I try to mount it with that plugin it takes a long time then fails. I checked the logs and found this

May 16 09:16:48 Dan-Storage kernel: I/O error, dev sdn, sector 96 op 0x0:(READ) flags 0x800 phys_seg 28 prio class 2

The drive was good when I took it out, so I don't suspect it's suddenly broken, but maybe the issue is with the USB reader?

Edit

Adding this information from the logs.

May 16 09:37:49 Dan-Storage kernel: REISERFS warning (device sdn1): sh-2006 read_super_block: bread failed (dev sdn1, block 128, size 512)

May 16 09:37:49 Dan-Storage kernel: REISERFS warning (device sdn1): sh-2021 reiserfs_fill_super: can not find reiserfs on sdn1

May 16 09:37:50 Dan-Storage unassigned.devices: Mount of 'sdn1' failed: 'mount: /mnt/disks/ZCT0S29F: wrong fs type, bad option, bad superblock on /dev/sdn1, missing codepage or helper program, or other error. dmesg(1) may have more information after failed mount system call.'

Edited May 16May 16 by DonnyTrump

I’m able to get into the files from my windows machine using YAReG. I’m copying things now but it’s extremely slow and time consuming. If this is what it takes though that’s ok, at least I can get to the stuff.

Try checkinmg filesystem on that disk, using the checkmark icon on UD.

On 5/17/2026 at 4:12 AM, JorgeB said:

Try checkinmg filesystem on that disk, using the checkmark icon on UD.

Managed to get the drive mounted, once I hooked it up via sata (had to get an adapter for power), it mounted right away and now I’m copying at a much faster speed. Thanks so much for the help!