Monday, January 23, 2006
RAIDZ
Jeff Bonwick's Weblog: "Enter RAID-Z.
RAID-Z is a data/parity scheme like RAID-5, but it uses dynamic stripe width. Every block is its own RAID-Z stripe, regardless of blocksize. This means that every RAID-Z write is a full-stripe write. This, when combined with the copy-on-write transactional semantics of ZFS, completely eliminates the RAID write hole. RAID-Z is also faster than traditional RAID because it never has to do read-modify-write.
Whoa, whoa, whoa -- that's it? Variable stripe width? Geez, that seems pretty obvious. If it's such a good idea, why doesn't everybody do it?"
RAID-Z is a data/parity scheme like RAID-5, but it uses dynamic stripe width. Every block is its own RAID-Z stripe, regardless of blocksize. This means that every RAID-Z write is a full-stripe write. This, when combined with the copy-on-write transactional semantics of ZFS, completely eliminates the RAID write hole. RAID-Z is also faster than traditional RAID because it never has to do read-modify-write.
Whoa, whoa, whoa -- that's it? Variable stripe width? Geez, that seems pretty obvious. If it's such a good idea, why doesn't everybody do it?"
# posted by Dr. Martin Menzel @ 12:36 AM 
