Btrfs RAID5/RAID6 Support Finally Get Fixed

[Yoshi]

The btrfs mailing list isn't that pleased about the article. Maybe Michael should post an update, stating that this patch doesn't fix ALL the outstanding issues with raid5/6

http://www.spinics.net/lists/linux-btrfs/msg60684.html

[starshipeleven]

Are there more things to address (besides code quality)

Quite a bit, so don't jump on it yet. This was just major scary shit that was supposed to require large sweeping changes to fix, but the non-implemented stuff is still not implemented.

[starshipeleven]

Btrfs is smelling really rotten... Rancid butter?

You smell like bullshit.

[FireBurn]

If this is a bug fix, I'd expect it to go into 4.9 and be back ported to the stable kernels

[ssam]

This is pretty good news. The worst case of "more or less fatally flawed, and a full scrap and rewrite to an entirely different raid56 mode on-disk format may be necessary to fix it" turns out not to be true. I'll probably stick with BTRFS raid 1 a bit longer though.

The write hole is not unique to BTRFS, and the checksumming reduces its impact. So I don't see that as a big deal.

[caligula]

AFAIK even with the patches the write hole still exists, parity is still not checksummed and scrub will still not repair. It just fixes a scrub race condition which is not even mentioned in the wiki.

On top of that it's also damn slow.

[timofonic]

Btrfs is smelling really rotten... Rancid butter?

[darkbasic]

AFAIK even with the patches the write hole still exists, parity is still not checksummed and scrub will still not repair. It just fixes a scrub race condition which is not even mentioned in the wiki.

[waxhead]

Does this need a new on disk format or its just a driver thing?

From what I was able to piece together it is just a race condition and does not require a format change. The disk format is actually marked as stable and newer kernels will support older formats if a format change is necessary.

[Nille]

Does this need a new on disk format or its just a driver thing?