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Lost a disk while doing a data-rebuild on another disk, dual parity, but getting a lot of errors? What to do RIGHT THIS MINUTE?

Featured Replies

Hello! I've been migrating off my Drobo 5C to an Unraid system, and thought I was on the final straight: Drobo is empty, I have dual parity set up, and I just swapped the 8TB that has some SMART errors for a 14TB that doesn't, all that's left is to rebuild the data. Reached this point 4 hours ago.

Aaaaand then this happens. Disk 4 drops out, though honestly seemed to be doing just fine. Dual parity keeps things alive, except... Wait, that a LOT of errors!

 

Parity 2 still reads as being connected, but if I go to the attributes it shows the error (Smartctl open device /dev/sdg failed), which is the same error as with Disk 4.

 

After checking the cables, I have confirmed that both drives are going into the same PCIe SATA card, so seems like THAT is the one that's borked.

 

What I'm asking for right now:

What should I do right now?!

I have paused the data-rebuild because it was throwing so many errors. Array is still running, because stopping it would cancel the data-rebuild.

 

Potential things I can think of (ordering a new SATA PCIe card is a given, but in the meantime):

If I remove the Cache 2 drive, that would enable two SATA ports on the motherboard that are currently disabled (the M.2 slot and the SATA ports share lanes). Can the array recognize this even though the SATA controller they're going through has changed?

 

image.thumb.png.338d3852d4ee67dacee283355ffcc919.png

image.png.0b50b57d56acbbee4fb662bce40636ba.png

image.png.3984a88ca223f4d4be534a18b7da9852.png

 

Solved by JorgeB

  • Author

Welp, I ended up stopping the array, powering down, taking out the cache M.2, and plugging the two drives into the mobo.

 

At first it looked like all was fine? All the drives were found and went into their correct slots in the listing, looked as if all I had to do was hit Start Array and it'd be good.

 

But after starting it, it's now showing the drives still in the same states, with the addition that they're listed as unmountable.

Despite this it wants to do a data-rebuild on a 14TB drive, looks like Disk 2, even though it's unmountable?

 

Kinda lost right now to be honest.

  • Author

image.thumb.png.d8814adcc06020737a874551b9d12557.png

Screenshot of the situation. I've paused the data-rebuild again. Also stopping the array isn't available because there's a BTRFS operation going. Though I have no idea what exactly it's doing (probably some cleanup from removing that one cache drive)...

  • Author

Sitrep: BTRFS operation done, can stop the array again if necessary.

  • Author
6 minutes ago, JorgeB said:

Check filesystem on both unmountable disks, run it without -n

Disk 4:

Quote

 

Phase 1 - find and verify superblock...

bad primary superblock - bad CRC in superblock !!!

attempting to find secondary superblock...

.found candidate secondary superblock...

verified secondary superblock...

writing modified primary superblock

sb root inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 128

resetting superblock root inode pointer to 128

sb realtime bitmap inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 129

resetting superblock realtime bitmap inode pointer to 129

sb realtime summary inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 130

resetting superblock realtime summary inode pointer to 130

Phase 2 - using internal log

- zero log...

ERROR: The filesystem has valuable metadata changes in a log which needs to be replayed. Mount the filesystem to replay the log, and unmount it before re-running xfs_repair. If you are unable to mount the filesystem, then use the -L option to destroy the log and attempt a repair. Note that destroying the log may cause corruption -- please attempt a mount of the filesystem before doing this.

 

Disk 2:

Quote

 

Phase 1 - find and verify superblock...

bad primary superblock - bad CRC in superblock !!!

attempting to find secondary superblock...

.found candidate secondary superblock...

verified secondary superblock...

writing modified primary superblock

Phase 2 - using internal log

- zero log...

ERROR: The filesystem has valuable metadata changes in a log which needs to be replayed. Mount the filesystem to replay the log, and unmount it before re-running xfs_repair. If you are unable to mount the filesystem, then use the -L option to destroy the log and attempt a repair. Note that destroying the log may cause corruption -- please attempt a mount of the filesystem before doing this.

 

 

  • Community Expert
3 minutes ago, jubuttib said:

If you are unable to mount the filesystem, then use the -L option

Unraid has already determined the disks can't be mounted, so you have to use -L

  • Author
1 minute ago, trurl said:

Unraid has already determined the disks can't be mounted, so you have to use -L

So run it without -n, but with -L?

  • Community Expert

yes

  • Author

Disk 4:

Phase 1 - find and verify superblock...
sb root inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 128
resetting superblock root inode pointer to 128
sb realtime bitmap inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 129
resetting superblock realtime bitmap inode pointer to 129
sb realtime summary inode value 18446744073709551615 (NULLFSINO) inconsistent with calculated value 130
resetting superblock realtime summary inode pointer to 130
Phase 2 - using internal log
        - zero log...
ALERT: The filesystem has valuable metadata changes in a log which is being
destroyed because the -L option was used.
        - scan filesystem freespace and inode maps...
clearing needsrepair flag and regenerating metadata
sb_icount 0, counted 10624
sb_ifree 0, counted 332
sb_fdblocks 2441087415, counted 332646411
        - found root inode chunk
Phase 3 - for each AG...
        - scan and clear agi unlinked lists...
        - process known inodes and perform inode discovery...
        - agno = 0
        - agno = 1
        - agno = 2
        - agno = 3
        - agno = 4
        - agno = 5
        - agno = 6
        - agno = 7
        - agno = 8
        - agno = 9
        - process newly discovered inodes...
Phase 4 - check for duplicate blocks...
        - setting up duplicate extent list...
        - check for inodes claiming duplicate blocks...
        - agno = 0
        - agno = 1
        - agno = 5
        - agno = 8
        - agno = 2
        - agno = 4
        - agno = 6
        - agno = 9
        - agno = 3
        - agno = 7
Phase 5 - rebuild AG headers and trees...
        - reset superblock...
Phase 6 - check inode connectivity...
        - resetting contents of realtime bitmap and summary inodes
        - traversing filesystem ...
        - traversal finished ...
        - moving disconnected inodes to lost+found ...
Phase 7 - verify and correct link counts...
Maximum metadata LSN (1:106489) is ahead of log (1:2).
Format log to cycle 4.
done

Disk 2:


Phase 1 - find and verify superblock...
Phase 2 - using internal log
        - zero log...
ALERT: The filesystem has valuable metadata changes in a log which is being
destroyed because the -L option was used.
        - scan filesystem freespace and inode maps...
clearing needsrepair flag and regenerating metadata
sb_icount 128, counted 320
sb_ifree 122, counted 280
sb_fdblocks 3403949121, counted 3413601993
        - found root inode chunk
Phase 3 - for each AG...
        - scan and clear agi unlinked lists...
        - process known inodes and perform inode discovery...
        - agno = 0
        - agno = 1
        - agno = 2
        - agno = 3
        - agno = 4
        - agno = 5
        - agno = 6
        - agno = 7
        - agno = 8
        - agno = 9
        - agno = 10
        - agno = 11
        - agno = 12
        - process newly discovered inodes...
Phase 4 - check for duplicate blocks...
        - setting up duplicate extent list...
        - check for inodes claiming duplicate blocks...
        - agno = 0
        - agno = 2
        - agno = 3
        - agno = 8
        - agno = 10
        - agno = 1
        - agno = 4
        - agno = 6
        - agno = 5
        - agno = 9
        - agno = 12
        - agno = 7
        - agno = 11
Phase 5 - rebuild AG headers and trees...
        - reset superblock...
Phase 6 - check inode connectivity...
        - resetting contents of realtime bitmap and summary inodes
        - traversing filesystem ...
        - traversal finished ...
        - moving disconnected inodes to lost+found ...
Phase 7 - verify and correct link counts...
Maximum metadata LSN (1:1616054) is ahead of log (1:2).
Format log to cycle 4.
done

 

  • Community Expert

Restart the array in Normal mode and I would now expect the drives to mount fine.

  • Author
1 minute ago, itimpi said:

Restart the array in Normal mode and I would now expect the drives to mount fine.

Hmm, seems like they did, but Disk 4 is still marked as disabled for some reason. =/

 

image.thumb.png.bf3edb1c91b7c55128d3882b8a4c9116.png

  • Community Expert

That was to repair the filesystem, once a disk gets disabled it needs to be rebuilt, if the contents look correct for both emulated disks you can rebuild on top, disk2 looks mostly empty, though.

 

Recommend updating to 6.12.15 or 7.0.0 first, since there's a bug in previous release that can disabled a 3rd disk with dual parity.

 

 

  • Author

Right, so update first, I think 6.12.15 is probably safer than straight to 7...

 

What after that? Is it something like:

 

  1. Set Disk 4 to nothing
  2. Start in maintenance mode
  3. Stop
  4. Set Disk 4 to the drive
  5. Start in normal mode

Something like that?

 

EDIT: Update to 6.12.15 done.

Edited by jubuttib

  • Community Expert

Yep

  • Author

OK, did that, data-rebuild going on with the two drives.

 

Thanks for all the help @JorgeB, @trurl & @itimpi! Would love to mark all you guys as solutions, but alas that's not possible.

 

Let's hope the other SATA PCIe card doesn't shit the bed before the rebuild is done...

Edited by jubuttib

  • Community Expert

Do you have a lost+found share after repair? 

  • Author
Just now, trurl said:

Do you have a lost+found share after repair? 

image.png.2fbe0e5f68dd49e5390863edcdcdfecd.png

Not that I can see?

  • Community Expert

Any errors during the rebuild post new diags before rebooting.

  • Author
5 minutes ago, JorgeB said:

Any errors during the rebuild post new diags before rebooting.

Will do!

  • Community Expert
10 minutes ago, jubuttib said:

image.png.2fbe0e5f68dd49e5390863edcdcdfecd.png

Not that I can see?

That is good.    You only get a lost+found share created if the recovery process finds any files for which it cannot find the directory entry to give the files their correct name.

  • Author
On 2/17/2025 at 9:17 PM, JorgeB said:

Any errors during the rebuild post new diags before rebooting.

Rebuild just finished without any errors, many thanks once more for all the help!

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