Comment by the8472
6 years ago
It's not a bug, but an unimplemented feature. They never made any promise that raid5 is production-ready.
Pretty much all software-raid systems suffer from it unless they explicitly patch over it via journaling. Hardware raid gets away with it if it has battery backups, if they don't they suffer from exactly the same problem.
... hence the desire to use ZFS, which skips trying to present a single coherent block device and performs parity at the file (chunk) level.