teuthology: use btrfs to back osds
each sepia node has a scratch /dev/sdb. (re)format it with btrfs on each run and put the osd data there.
#2 Updated by Sage Weil almost 10 years ago
I think the key here is to have some per-node metadata indicating which disks (e.g. /dev/sdb) are available as scratch. Then the ceph task will grab one of the list for each (btrfs-backed) osd, format it, etc. It might even make sense to partition it into a raw journal and btrfs piece.
It would be cute to be able to specify how a disk is carved up in a flexible way, but I don't think we need any of that now.