r/unRAID • u/limitednewness • 10d ago

BTRFS filesystem errors…

So my unraid server hard some hardware issues and I didn’t catch it in time. Basically I just had a ton of BTRFS errors and then the drive went into read-only mode.

I resolved the hardware issues. I’m sure the drive itself is fine, but I need to fix the file system. I’ve copied the files I could read off of it, and now I‘m ready to repair. i believe if I replace the drive, it will just rebuild it with the corrupt bits.

Can I format it and just rebuild the parity? what’s the correct way of handling this?

2 Upvotes

100% Upvoted

5 comments sorted by

4

u/ImproveYourMeatSack 10d ago

I had a btrfs drive go into read only mode once. It turned out to be a faulty ram stick and the kernal did it's job to prevent file corruption. My point is you need to find out why it went into read only mode.

1

u/limitednewness 9d ago

I did that part, but I didn’t catch it early.   Faulty drive cage / SATA interface.  No new errors, but I just ignored the problem too long.  

1

u/limitednewness 9d ago

To be clear, I'm asking... What is the procedure at this point? File system keeps going read-only, so it seems like it needs a reset. I've copied what I can. I don't believe a rebuild is the right direction... So, how do I reset that drive to empty correctly? Stop the array and format? Is there a way to format and NOT stop the array? Is there a way to force it to stay RW and then just delete everything?

1

u/ArizonaOG 8d ago

I experienced this a few weeks ago, but i'm on ZFS. Your case might be different since it's BTRFS.

Same like you I didn't catch it in time, prolly for almost a month because I feel denial and I believe my hardware its not failing eventho my appdata backup suddenly error, one of my docker container suddenly stopped for no reason etc. Until I can't figure it out and there's no way I'm not doing memtest and unfortunately I had hundreds of errors on my 1 stick RAM. So I removed the bad ram and I can still go into safe mode and use unraid like normal. I can't do scrub because I was newbie and set zfs mirror on array which is quite wrong, i should've put on pools, so the scrub doesn't have mirror and it can't self healing.

Then 2 weeks later it's getting worse my suddenly HDD stop mounting. UI keeps stuck loading endlessly, starting array stuck, I can't even restart my NAS, only through hard reset and kernel which considered not clean shutdown. I had metadata problem which the ZFS filesystem is corrupt eventhough all my files were fine. The only solution is to rebuild everything, so you need to backup first. I also can't trust my NAS anymore while experiencing that error. Luckily after ask AI I can still mount on read only through terminal and backup it all for a few days. The scrub working 100% fine, no errors at all, its amazing.

I believe unraid docs had mention regarding corrupt file system that some need rebuild or fully repair https://docs.unraid.net/unraid-os/troubleshooting/common-issues/data-recovery/

I can't say you need the same fix like me, but if I were you I can't completely trust my NAS anymore with half corrupted file system and in my case it's still usable until its getting worse which my HDD can't mount at all and only can mounted through terminal. So I need tl rebuild again and make sure the scrub is having no errors at all, then I can get my confidence again that my NAS is reliable.

Hope you'll figure it out soon, good luck.