User manual

Table Of Contents
SuperTrak EX Series User Manual
248
Hot Spare Drive
A hot spare is a physical drive that is available to a disk array but not actually a
part of it. If you designate a spare drive, SuperTrak will replace a failed physical
drive in a disk array with the hot spare drive automatically. See “Creating a Spare
Drive” on page 99 or page 179.
Compared to the failed drive, the replacement drive must be:
The same media type, HDD or SDD
Equal or larger capacity
There are two types of hot spare drive:
Global – An unassigned physical drive available to any logical drive on the
Host PC.
Dedicated – An unassigned physical drive that can only be used by a
specified logical drive.
There is another property you can assign to a hot spare drive:
Revertible – A revertible spare drive will return to spare status when the
failed drive is replace with a new drive. See “Transition” on page 256.
Whenever possible, having a spare drive for your RAID system is good protection
against physical drive failure. Even though the spare drive is assigned to a disk
array, the rebuild operation is said to apply to a logical drive.
If you do not have a spare drive, but the Auto Rebuild function is enabled, the
critical disk array will begin to rebuild as soon as you replace the failed physical
drive with an unconfigured physical drive of equal or greater size. See “Making
Background Activity Settings” on page 137.
Partition and Format the Logical Drive
Like any other type of fixed disk media in your system, a RAID logical drive must
also be partitioned and formatted before use. Use the same method of
partitioning and formatting on an logical drive as you would any other fixed disk.
See “Appendix A: Partition and Format” on page 285.
RAID Level Migration
To migrate a disk array is to do one or both:
Change its RAID level
Increase the number of physical drives (sometimes called expansion)
On SuperTrak, RAID level migration is performed on the disk array but it applies
to the logical drives. Migration takes place on an existing Functional disk array
without disturbing the existing data. While the disk array is migrating, you can