Hi everyone! I would like to use Btrfs' RAID in a somewhat unorthodox
way, but if it's possible then it would be perfect for my use case.
Suppose I have a RAID1C3 filesystem spanning 3 hard drives A, B and C,
each of the same size. A and B are at different physical locations after
the initial mkfs.
When I want to make a backup, I would plug in drives C and A, and send
them a snapshot. Once in a while, I would go to drive B's location
carrying drive C with me, then I would plug in drives C and B, waiting
for Btrfs to replicate the missing data on drive B.
It would be easier than sending the snapshots across 3 different
filesystems, and most importantly, I could run a scrub with auto-repair
on C+A or C+B.
I did some quick tests with 3 USB keys, and it *seems* to work. But I
don't know how to be notified when the replication is done (which seems
to run automatically/silently in the background). I also don't know
whether it's a reliable method or not.
Any thoughts about this?
Thanks!
Timothée
