Product manual

Chapter 7: Technology Background
253
drive. In this example, physical drive 3 failed and the array is rebuilt using
physical drive 6, the spare drive.
When the rebuild is complete, the spare drive has replaced the failed drive. In this
example, failed drive 3 was replaced by spare drive 6. The disk array now
consists of physical drives 1, 2, 4 and 6.
There is no spare drive at this moment. Even if physical drive 5 is of adequate
capacity, it has not been designated as a spare, therefore the controller cannot
use it as a spare.
At this juncture, you would replace the failed drive in slot 3 with a new one.
If you wanted to make the new drive in slot 3 a member of the disk array and
return the drive in slot 6 to spare drive status, you would use the Transition
function.
Transition copies the data from the spare drive that became part of the array to
the target drive you specify.
In this example, you would select the disk array and specify physical drive 3 as
the target. Transition copies the data from drive 6 to drive 3. Then drive 3
becomes part of the disk array while drive 6 returns to spare drive status.
When Transition is finished, physical drives 1, 2, 3 and 4 belong to the disk array
and physical drive 6 is a revertible spare drive. The original configuration is
restored.