[kevincox]

Yeah, BTRFS is really not good for any sort of redundancy, not even very good for multi-disk in general.

1. The scheduler doesn't really exist. IIRC it is PID % num disks.

2. The default balancing policy is super basic. (IIRC always write to the disk with the most free space).

3. Erasure coding is still experimental.

4. Replication can only be configured at the FS level. bcachefs can configure this per-file or per-directory.

bcachefs is still early but it shows that it is serious about multi-disk. You can lump any collection of disks together and it mostly does the right thing. It tracks performance of different drives to make requests optimally and balances write to gradually even out the drives (not lasering a newly added disk).

IMHO there is really no comparison. If it wasn't for the fact that bcachefs ate my data I would be using it.