Optimized Mirror Resync

During a reboot following a system failure, or when a submirror that was offline is brought back online, DiskSuite performs an optimized mirror resync. The metadisk driver tracks submirror regions and knows which submirror regions may be out-of-sync after a failure. An optimized mirror resync is performed only on the out-of-sync regions. You can specify the order in which mirrors are resynced during reboot, and you can omit a mirror resync by setting submirror pass numbers to 0 (zero). (See "Pass Number" for information.)

A pass number of 0 (zero) should only be used on mirrors mounted as read-only.