On Jul 20, 2010, at 6:12 AM, v <victor_zh...@hotmail.com> wrote: > Hi, > for zfs raidz1, I know for random io, iops of a raidz1 vdev eqaul to one > physical disk iops, since raidz1 is like raid5 , so is raid5 has same > performance like raidz1? ie. random iops equal to one physical disk's ipos.
On reads, no, any part of the stripe width can be read without reading the whole stripe width, giving performance equal to raid0 of non-parity disks. On writes it could be worse then raidz1 depending on whether whole stripe widths are being written (same performance) or partial stripe widths are being written (worse performance). If it's a partial stripe width then the remaining data needs to be read off disk which doubles the IOs. -Ross _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
