Topic summary
RAID-Z
Extracted from the Wikipedia article Non-standard RAID levels.
RAID-Z
The ZFS filesystem provides RAID-Z, a data/parity distribution scheme similar to RAID 5, but using dynamic stripe width: every block is its own RAID stripe, regardless of blocksize, resulting in every RAID-Z write being a full-stripe write. This, when combined with the copy-on-write transactional semantics of ZFS, eliminates the write hole error. RAID-Z is also faster than traditional RAID 5 because it does not need to perform the usual read–modify–write sequence. RAID-Z does not require any special hardware, such as NVRAM for reliability, or write buffering for performance.