Product manual

VTrak M-Class Product Manual
252
During data migration, you will have access to the Logical Drive but it will respond
more slowly to read/write tasks because of the additional operation. The time
required for data migration depends on the size of the disk drive.
See “Logical Drive PDM” on page 144.
Transition
Transition is the process of replacing a revertible spare drive that is currently part
of a disk array with an unconfigured physical drive or a non-revertible spare. The
revertible spare drive returns to its original status.
Transition enables you to designate one or more drives in your subsystem as
permanent spares. If a spare drive is needed to repair a disk array, you can return
the spare drive to spare status using this feature.
The following diagrams explain a situation where you might choose to use the
Transition function.
In the example above, there is a four-drive RAID 5 disk array and a global spare
drive. Physical drives 1, 2, 3 and 4 belong to the disk array. Physical drive 5
remains unconfigured. Physical drive 6 is a revertible spare drive.
If a physical drive fails in a disk array and there is a spare drive of adequate
capacity available, the controller automatically rebuilds the array using the spare