I have 2 parity disks in my unraid system, both parity disks are fine. In the array I have 2 disks with a problem, disk 4 yellow triangle says disk contents emulated and disk 6 red x says disk is disabled. Both say BTRFS unmountable no file system. The file system is BTRFS Encrypted. This started after the server lost power due to a building wide power All smart tests showed OK for both drives.

outage. tower-diagnostics-20250525-1948.zip

If anyone could advise how I can fix this problem I would be very thankful. Is there a procedure I could follow?

I started the array in maintenance mode and ran btrfs check on both drives:

ERROR: superblock checksum mismatch
ERROR: superblock checksum mismatch
No valid Btrfs found on /dev/mapper/md4p1
ERROR: cannot open file system
Opening filesystem to check...

Should not have started to rebuild if the disk is unmountable, unassign disk4 and post new diags after array start.

Ok will do thank you @JorgeB I will try

@JorgeB I removed disk 4 as you suggested and ran a new diagnostic right after. I did not touch Disk 6. Here is the new diagnostic. tower-diagnostics-20250526-1814.zip

No btrfs filesystem is being detected on those disks, with the array running post the output from btrfs fi show

Then stop the array and post the output fromblkid

@JorgeB I ran both commands and posted the output below. Thank you for the help you are providing.

root@Tower:~# btrfs fi show

Label: none uuid: a03b8944-2fb1-4c60-9cbe-7ca6b18cc789

Total devices 1 FS bytes used 7.15TiB

devid 1 size 10.91TiB used 9.25TiB path /dev/mapper/md1p1

Label: none uuid: 56f7e42d-cd5a-491c-bc94-3a35bcd46843

Total devices 1 FS bytes used 4.61TiB

devid 1 size 10.91TiB used 4.72TiB path /dev/mapper/md2p1

Label: none uuid: 87979a6f-edcb-4886-ba43-e909bd812a41

Total devices 1 FS bytes used 11.90TiB

devid 1 size 12.73TiB used 12.56TiB path /dev/mapper/md5p1

Label: none uuid: 104b676a-602f-4189-9eea-5ef5b133791d

Total devices 1 FS bytes used 144.00KiB

devid 1 size 10.91TiB used 3.02GiB path /dev/mapper/md7p1

root@Tower:~# blkid

/dev/sda1: LABEL_FATBOOT="UNRAID" LABEL="UNRAID" UUID="2736-60C3" BLOCK_SIZE="512" TYPE="vfat"

/dev/loop1: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/sdf1: UUID="0e1a1f2a-5d25-467e-953b-fe337dbeef3f" TYPE="crypto_LUKS" PARTUUID="c826d723-882d-4907-82bb-e8ab841d9ecf"

/dev/sdg1: LABEL="cache" UUID="16723579336533422522" UUID_SUB="6378610447672026771" BLOCK_SIZE="4096" TYPE="zfs_member"

/dev/loop0: BLOCK_SIZE="131072" TYPE="squashfs"

/dev/sdk1: UUID="f0c23d59-e7db-44da-b2ad-15487ef39c9c" TYPE="crypto_LUKS" PARTUUID="b6634d83-c86d-4e20-ac51-320fe7de79bc"

/dev/sdl1: UUID="67e6d85e-9437-4ceb-9fa8-f7d621ab2eb8" TYPE="crypto_LUKS" PARTUUID="ed182c8d-4edd-4ae4-9550-8f55d7eeac1e"

/dev/sdd1: UUID="80e22954-d4df-4d2f-be1c-3c61def4b93d" TYPE="crypto_LUKS" PARTUUID="c3a8ac52-4e24-4f15-a3cb-f33d88ef9e08"

/dev/sdb1: UUID="849fe34a-2b77-4064-bf6e-9147c2e66418" TYPE="crypto_LUKS" PARTUUID="cf4cf758-71fa-40be-896e-bbc8e994d7a1"

/dev/sdi1: PARTUUID="72e49836-63e1-4190-92f5-b4f59cf70df5"

/dev/sde1: UUID="55d6b5c6-4cc7-4189-9a81-5b1f73d3192f" TYPE="crypto_LUKS" PARTUUID="944feb2d-12b1-45b8-a40a-18725dbbfb3b"

/dev/sdj1: PARTUUID="c6abf532-e821-479c-9c47-e26d3074e9a8"

For disk6, unassign the disk and see if it mounts with UD.

For disk4, since it's already being rebuilt, it probably won't work, but it won't hurt to try.

I ended up getting all sorts of errors, I was able to backup my most important stuff off of Unraid due to having 2 parity drives. Might be easier to delete the whole array and start over?

No need to start all the array, at most reformat those two disks.

Sorry to butt in, but I was considering switching from XFS to BTRFS. Is the issue here due to the BTRFS?

Aside from the power issue that could happen to anyone ( I have had 100's of shut downs in my old now dead server with XFS and I had no issues with drives ), what caused the issue here?

Thanks in advance

11 hours ago, Renew said:

Is the issue here due to the BTRFS?

Not directly, something happened to the devices, no filesystem is being found.