Comment Re:The native Linux standard is called MD (madm, L (Score 4, Informative) 247
When you have a redundant array such as two mirrored disks, you have the question of "which one is wrong?" when data corruption occurs.
The magic of ZFS is that it is able to checksum the data and metadata, so when you have a mismatch it knows which one is correct and is able to repair it from the mirror. AFAIK this is not something which MD is capable of, because it needs cooperation from both the RAID stack and the filesystem itself.
BTRFS has to do the same thing (manage RAID itself) for the same reason.