Currently Being ModeratedNov 2, 2012 8:37 PM (in response to William Martin1)
Initializing? that sounds like a problem. Unless you mean either scrubbing/conditioning or rebuilding.
The former can be initiated via RAID Admin, and makes the XServe RAID check every block on the disk.
The latter may happen if a disk fails and the data needs to be replicated/rebuilt on a spare drive.
Initializing, as its name implies, involves setting up an new array. This doesn't usually (ever?) happen on its own, but only at the behest of someone using RAID Admin to manipulate the array.
As for the duration - if you're using RAID 5, creating the array performs a scrub of each disk to verify its integrity, as well as creating the initial parity data. If you enable the background option, the array is available for use immediately, even while the scrub is progressing.