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I destroyed my cachepool config

Featured Replies

Hi,

 

I tried to remove the 2nd SSD of my cachepool.

 

It used to be a raid1 - since I wanted to remove one disk, I converted it back to single. 

Then I removed the 2nd SSD from the config (new config).

But I guess I missed a step. Now I can only wipe the data - which I want to avoid. 

 

So how do I either finish the conversion or restore it back? 

 

 

btrfs-select-super -s 1 /dev/nvme0n1p1 
warning, device 2 is missing
warning, device 2 is missing
ERROR: cannot read chunk root
ERROR: open ctree failed

 

btrfs-select-super -s 1 /dev/nvme1n1 
No valid Btrfs found on /dev/nvme1n1
ERROR: open ctree failed

Solved by JorgeB

  • Community Expert
3 minutes ago, patrickstigler said:

since I wanted to remove one disk, I converted it back to single. 

Single in btrfs is between RAID0 and spanning, i.e. one big "drive" made of both, so both are required. 

Should have removed one while in RAID1 (only config that actually tolerates a drive loss), and THEN converted afterwards.

 

Can you still add the 2nd drive back? If so it should just work again.

Edited by Kilrah

  • Author

Ok, wrong order :-(

 

Unfortunately not

image.thumb.png.ace5c34eefe75d7bec7428206a79d95c.png

  • Community Expert

Post the output of

btrfs fi show

 

  • Author

warning, device 2 is missing
warning, device 2 is missing
ERROR: cannot read chunk root
Label: none  uuid: 53b61841-b900-45f6-a9b6-7446d79b46bc
        Total devices 2 FS bytes used 282.78GiB
        devid    1 size 465.76GiB used 14.00GiB path /dev/nvme0n1p1
        *** Some devices missing

  • Community Expert

Type

sfdisk /dev/nvme1n1

then type

2048

and enter, post the results

  • Author

Created a new DOS disklabel with disk identifier 0x8744012d.
Created a new partition 1 of type 'Linux' and of size 931.5 GiB.
Partition #1 contains a btrfs signature.

Do you want to remove the signature? [Y]es/[N]o: 
 

  • Community Expert

Type N and enter to keep the signature, then type

write

followed by enter, post new output of

btrfs fi show

 

  • Author

Label: none  uuid: 53b61841-b900-45f6-a9b6-7446d79b46bc
        Total devices 2 FS bytes used 282.78GiB
        devid    1 size 465.76GiB used 14.00GiB path /dev/nvme0n1p1
        devid    2 size 931.51GiB used 290.06GiB path /dev/nvme1n1p1
 

 

looks better I guess?!

  • Community Expert

Try re-starting the array, the pool should mount now.

  • Community Expert
  • Solution

If OK then convert the pool to raid1, once done you can remove the device and the pool will automatically be converted to single.

  • Author

Thank you so much - again. 

 

So enjoy the beer ;-D

  • Community Expert

Thanks for beer money!

  • Author

Welcome :-D 

 

Unfortunately I still have some trouble, while I want to convert back to singe drive.

 

root@Server:~# btrfs balance start -f -dconvert=single -mconvert=single /mnt/cache
ERROR: error during balancing '/mnt/cache': Input/output error
There may be more info in syslog - try dmesg | tail
root@Server:~# dmesg | tail
[276079.589839] BTRFS info (device nvme0n1p1): relocating block group 4693758574592 flags system|dup
[276079.611808] BTRFS info (device nvme0n1p1): found 3 extents, stage: move data extents
[276079.624923] BTRFS info (device nvme0n1p1): relocating block group 4692684832768 flags metadata|dup
[276084.175103] BTRFS info (device nvme0n1p1): found 25823 extents, stage: move data extents
[276086.154762] BTRFS info (device nvme0n1p1): relocating block group 1636480057344 flags data|raid1
[276086.348070] BTRFS warning (device nvme0n1p1): csum failed root -9 ino 922 off 130379776 csum 0x3019a12b expected csum 0x3ed50501 mirror 2
[276086.348083] BTRFS error (device nvme0n1p1): bdev /dev/nvme0n1p1 errs: wr 0, rd 0, flush 0, corrupt 807, gen 0
[276086.357072] BTRFS warning (device nvme0n1p1): csum failed root -9 ino 922 off 130379776 csum 0x3019a12b expected csum 0x3ed50501 mirror 2
[276086.357079] BTRFS error (device nvme0n1p1): bdev /dev/nvme0n1p1 errs: wr 0, rd 0, flush 0, corrupt 808, gen 0
[276086.604873] BTRFS info (device nvme0n1p1): balance: ended with status: -5

  • Community Expert

Balance is aborting because it's finding some corrupt data, if you don't have ECC RAM it may be a good idea to run memtest first, then scrub the pool and look at the syslog for the list of corrupt files, delete/restore those from a backup, then run another scrub to confirm there are no more errors and try to convert again.

  • Author

I ran Memtest, the whole weekend, last week :-D

I got 2 broken modules. So the other ones, currently working fine - at leased I'd say so.

 

I tried to scrub it. But there is one Uncorrectable error. So what to do now?

 

UUID: 53b61841-b900-45f6-a9b6-7446d79b46bc Scrub started: Mon Apr 1 16:58:22 2024 Status: aborted Duration: 0:07:20 Total to scrub: 354.71GiB Rate: 795.44MiB/s Error summary: csum=1 Corrected: 0 Uncorrectable: 1 Unverified: 0

  • Community Expert
2 hours ago, JorgeB said:

look at the syslog for the list of corrupt files, delete/restore those from a backup, then run another scrub to confirm there are no more errors and try to convert again.

 

  • Author

only broken sectors ... 

 

I justed wiped the disk, and recovered from the backup. Took a while, but it seems to work.

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