Description of Issue: I recently completed a rebuild of Disk 6 from Parity. Following the subsequent reboot, both the newly rebuilt drive (Disk 6) and an existing drive (Disk 9) are showing as "Unmountable: Unsupported or no file system.

Current Array Status: The array is started, but:

• Disk 9 is being emulated (red "X" in the GUI).

• Both Disk 6 and the emulated Disk 9 are listed as unmountable.

• I currently have no access to files on either of these disks through the Unraid shares.

Console Corruption Errors: The physical console displays critical XFS metadata corruption errors for Disk 9 (md9p1):

XFS (md9p1): Metadata corruption detected at xfs_buf_ioend...

XFS (md9p1): Unmount and run xfs_repair

XFS (md9p1): metadata I/O error in "xlog_recover_items_pass2..."

Hardware Configuration: The two affected disks are on separate controllers:

• Disk 6: Connected via an LSI SAS HBA card.

• Disk 9: Connected via the onboard SATA port on the motherboard.

• Boot Flash: Samsung Flash Drive FIT (Logs show normal initialization as sda, despite intermittent -71 enumeration errors during boot).

Troubleshooting Steps Taken:

1. External Verification: I pulled the physical Disk 9 and connected it to a Windows machine via SATA dock. DiskInternals Linux Reader confirmed the data is intact and readable, but Unraid cannot mount the emulated version.

2. Services: Plex Media Server is down as a result.

OS Version: 7.2.3

Questions for the Community: What is the safest way to proceed?

Thanks in advance for your help!

unraid-diagnostics-20260404-1632.zip

The first step is to check filesystem on both

The xlog_recover_items_pass2 error with error 117 (EUCLEAN) means XFS is refusing to replay its journal because it detected corruption in the log itself. This is recoverable but needs care.

Good news: DiskInternals reading the physical disk successfully means the disk hardware is fine. The issue is either the emulated reconstruction introduced log inconsistency during the parity rebuild, or Disk 9 had an unclean shutdown that left the journal in a state the kernel cannot safely replay.

Steps to try:

First, from the Unraid terminal while the array is started (even in degraded state), run a dry-run check without changing anything:

xfs_repair -n /dev/md9p1

Second, if that shows repairable errors, run it without the -n flag:

xfs_repair /dev/md9p1

If xfs_repair itself complains about a dirty log, you may need:

xfs_repair -L /dev/md9p1

This zeros the journal, which loses any in-flight writes from the last session but the data on disk stays intact.

For Disk 6 being unmountable after rebuild: run the same xfs_repair -n /dev/md6p1 dry run first. Post the output from both so we can see what the repair tool finds before you commit to changes.

Also worth running smartctl -a /dev/sdX on the physical Disk 9 device to verify no underlying hardware errors appeared.

Thank you for the quick assistance!

Please see the attached logs of the dry-run checks for both drives.

Let me know if I can proceed without the -n flag.

Thanks!

Log disk 6 (xfs_repair -n).txt Log disk 9 (xfs_repair -n).txt

See the link above, run the check using the GUI, it will show a FIX button if corruption is detected, which it likely will be, i will also also to zero the log if needed, just follow the flow.

17 hours ago, Rian Kelly said:

from the Unraid terminal

For future reference, no reason to do any of that from the terminal.

19 minutes ago, JorgeB said:

See the link above, run the check using the GUI, it will show a FIX button if corruption is detected, which it likely will be, i will also also to zero the log if needed, just follow the flow.

Thanks trurl.

I ran the file system check on both disks using the GUI. Both were showing a long list of errors, so I clicked the FIX button. For disk 9 only, the ZERO LOG button appeared and I used it.

At the end of the process, I got the message "File system corruption fixed" for both disks.

I stopped the array and restart in normal mode.

Now the disk 6 and 9 are showing almost empty, and disk 9 is being emulated (red "X" in the GUI). I have no access to files on either of these disks through the Unraid shares.

What should I do next?

Post new diagnostics

Here's the new diagnostics.

Thanks

unraid-diagnostics-20260406-1028.zip

I don't see any lost+found from the repair. Did you format the unmountable disks?

It would be very strange just running the filesystem check making the disks empty; something else was likely done.

For disk9, you can still mount the actual disk outside the array, if the data is there, then resync parity instead of rebuilding on top.

As for disk6, was it mountable and with data when the rebuild was done?

1 hour ago, trurl said:

I don't see any lost+found from the repair. Did you format the unmountable disks?

No, I did not format the disks.

Just did the procedure as described in my previous message.

Here a copy of the file check logs if it helps.

xfs_repair status Check Disk 6.txt xfs_repair status Check Disk 9.txt

55 minutes ago, JorgeB said:

It would be very strange just running the filesystem check making the disks empty; something else was likely done.

I have not done anything else except the File System Check procedure.

For disk9, you can still mount the actual disk outside the array, if the data is there, then resync parity instead of rebuilding on top.

Do you mean pull out disk 9 and check with a PC? If not, how do you mount the disk outside the array with the GUI?

As for disk6, was it mountable and with data when the rebuild was done?

The original disk 6 (4 TB) was emulated before it was removed and replaced with a new one (8 TB). The rebuild was done and I ended up as described in my original post with the 2 disks unmountable.

FYI, I checked the original disk 6 with DiskInternals Linux Reader and the data look all there and readable. Also did a backup of disk 9 with DiskInternals. I therefore have a backup of both disks.

Edited April 6Apr 6 by dthedj

This doesn't make sense, but try mounting the actual disk9. To do that, you need to stop the array, unassign disk9, then see if it mounts with the Unassigned Devices plugin.

For disk6, since it's already been rebuilt, you can restore the data from the old disk.

I stopped the array and selected "no device" for disk 9.

I did not restart the array without disk 9.

I tried to mount disk 9 using "Unassigned Disk Devices" but it did not work (see system log attached).

System Log - mounting disk 9.txt

Edited April 6Apr 6 by dthedj

The actual disk also has filesystem corruption.

Apr 6 15:08:25 unRAID kernel: XFS (sdd1): Mounting V5 Filesystem 7490ce1b-dccb-441d-8a42-0b4e5ea521dc

Apr 6 15:08:25 unRAID kernel: XFS (sdd1): Starting recovery (logdev: internal)

Apr 6 15:08:25 unRAID kernel: XFS (sdd1): Metadata corruption detected at xfs_buf_ioend+0xa8/0x380, xfs_inode block 0xcd86a0 xfs_inode_buf_verify

Apr 6 15:08:25 unRAID kernel: XFS (sdd1): Unmount and run xfs_repair

Apr 6 15:08:25 unRAID kernel: XFS (sdd1): First 128 bytes of corrupted metadata buffer:

Typically this is easily resolved by checking filesystem, but due to the previous results you had, which may indicate a more serious issue with the server, it may be better to clone the disk first before running it. You can do that with dd for example.

Since I already have a data backup of disk 9, I could skip the cloning and try to run again file system check, right?

For this, I suppose I need to reallocate disk 9 to array, start in maintenance mode and re-run the file system check?

15 minutes ago, dthedj said:

For this, I suppose I need to reallocate disk 9 to array, start in maintenance mode and re-run the file system check?

Nope, that would rebuild the current emulated disk9.

You can check filesystem from UD using the checkmark icon.

I ran check file system check from UD by clicking on the checkmark icon. See attached results.

Next, I click on the "RUN WITH CORRECT FLAG" button in pop-up window?

file system check disk 9 UD.txt

Yes

I clicked on the button and got the attached log.

Next I guess I click on "FORCE LOG ZEROING" ?

(sorry for being such a nooby)

log file system check disk 9 UD.txt

yes

Done the Zeroing and got the message "File system corruption fixed!". See attached log.

Now I can mount the disk 9 in UD and can browse the data which seam to be all available!

What should I do next?

log file zeroing log disk 9 UD.txt

11 minutes ago, dthedj said:

can browse the data which seam to be all available!

Is there a lost+found folder at the top level of the disk now?

yes