Drive Issues - Western Digital WD Serial ATA RAID Controller User Manual

WD SERIAL ATA RAID CONTROLLER
USER MANUAL
Q: How does the WD SATA RAID Controller provide storage and/or data
protection?
A: WD SATA RAID Controller implements two different types of RAID levels as follows:
RAID 0 (Stripe)
For capacity - The WD SATA RAID Controller array will be as big as the smallest hard drive
in the array times however many hard drives are in the array. Any larger hard drives will
simply be truncated. The truncated space on the bigger hard drives will then be unusable.
For sustained data transfers - Using WD SATA RAID Controller, a RAID 0 array consisting
of two hard drives will transfer at about twice the speed of the slowest hard drive in the array.
A RAID 0 array consisting of four hard drives will transfer at about three times the speed of
the slowest hard drive in the array.
RAID 1 (Mirror)
For capacity - The WD SATA RAID Controller array will be as big as the smallest hard drive
in the array. The larger hard drive will simply be truncated. The truncated space on the bigger
hard drive will then be unusable.
For sustained data transfers - The WD SATA RAID Controller array will write data at the
rate of the slowest hard drive in the array. The WD SATA RAID Controller array will read
data at twice the rate of the slowest hard drive in the array.

Drive Issues

Q: Can I add a drive to a WD SATA RAID Controller RAID array via hot-swap
and dynamically adjust the array size/configuration?
A: No. The WD SATA RAID Controller system does not support dynamically adjustable
RAID size/configurations.
Q: Do the HDDs on the WD SATA RAID Controller have to be the same size?
A: The HDDs that you use with the WD SATA RAID Controller do not have to be the same
size. If the sizes differ, the WD SATA RAID Controller will truncate the bigger hard drive so
the drives match. The resulting difference in hard drive space is unusable, so avoid using hard
drives of significantly different capacities.
Q: I already have an array on an existing WD SATA RAID Controller. Can I
move that array to my new WD SATA RAID Controller?
A: Yes. All WD SATA RAID Controllers read the arrays the same way and can be moved
from one controller to another.
Q: Can I take a drive used in a WD SATA RAID Controller array and access it
directly with a different controller, such as the one integrated on the
motherboard?
A: Only Single-drive striped (RAID 0) and Mirrored (RAID 1) array configurations allow the
drive(s) to be accessed individually on another controller. Multiple-drive striped (RAID 0)
will not work.
FREQUENTLY ASKED QUESTIONS - 31