Am I right, that a rebuild happens below file system level?

 

So, e.g. if Unraid is rebuilding a BTRFS drive, it could/would/should be possible to scrub that drive afterwards, to make 100% sure the rebuild did work as intended?

 

 

Short story why I'd want to do/know that: I knocked over my (running) Tower  LianLi ITX with 10 Bays https://www.picclickimg.com/d/l400/pict/173424939301_/RARE-Lian-Li PC-Q26A-Mini-ITX-PC-Case-with-four-additional.jpg

 

Pretty nice small enclosure, perfect for Unraid, only thing is, the drive bay locking mechanism is not super tight. So, even though all drives were spun down at that moment, and I'm almost certain that nothing bad happened to any of them, two of them did get disconnected for a few seconds, until I checked the seating of all of the drives, and ... of course ... Unraid red-X-ed them immediately.

 

Apparently the only way at that point is to let Unraid do a rebuild, to get them working again (I have two parity disks). Btw, the Wiki info seems to be outdated (I didn't see any "trust my array" option or whatever else).

 

So. from hard facts, since my accident may still have affected the integrity of multiple drives (including parity), I can't be 100% sure, that the (now running) rebuild is restoring perfectly valid data... but, in case my above thought is correct, a BTRFS scrub should be the way to ensure that after the rebuild is done.... right?

 

Some final thoughts: I love Unraid, until the moment something goes wrong. Had that a few times, and for every of that instances, I felt at no point really secure, to have found the right answer to that particular problem; Almost certainly it feels like having applied the wrong measure (like now, since a drive rebuild seems to be not the best thing in that particular case, if not the worst)...

2 hours ago, t3 said:

Am I right, that a rebuild happens below file system level?

Yep.

 

2 hours ago, t3 said:

So, e.g. if Unraid is rebuilding a BTRFS drive, it could/would/should be possible to scrub that drive afterwards, to make 100% sure the rebuild did work as intended?

Correct. 

Thanks for clarification!