Can I use btrfs-restore to restore ceph osds?

[Guido Winkelmann <guido-ceph@thisisnotatest.de>]

Hi,

I'm currently trying to re-enable my experimental ceph cluster that has been 
offline for a few months. Unfortunately, it appears that, out of the six btrfs 
volumes involved, only one can still be mounted, the other five are broken 
somehow. (If I ever use Ceph in production, it's probably not going to be on 
btrfs after this... I cannot recall whether or not the servers were properly 
shut down the last time, but even if not, this is a bit ridiculous.)

I cannot seem to repair the broken filesystem with btrfsck, but I can extract 
data from them with btrfs-restore.

If I want to restore this whole thing, can I just run btrfs-restore to recover 
the files that were on the broken volume, then make a new filesystem on the 
old partition, and finally copy over the directories and file restored by 
btrfs-restore? Or will that lose important information?

	Guido