OWC MERCURY ELITE PRO DUAL
DEVICE SETUP
8
2.3 RAID Settings
2.3.1 Changing the RAID Mode
The RAID mode is controlled by a dial on the rear of the unit, as shown below-left. The dial has four positions,
each labeled with a different RAID mode. To change the RAID mode, follow the simple steps below.
Adjust the RAID dial so that the arrow is pointing at the desired RAID mode. Each time the arrow is aligned
with a new mode, you will feel a slight click. A small flathead screwdriver works the best to adjust the dial.
When starting from a power on state, rotate the dial on the back of the enclosure
to the desired RAID mode, then unmount the drive and power off the Elite Pro
Dual. Next power on the Elite Pro Dual. The LEDs on the front will blink for a brief
time; once the blinking stops the drive is ready to use.
When starting from a power off state, rotate the dial on the back of the enclosure
to the desired RAID mode, then power on the Elite Pro Dual. The LEDs on the
front will blink for a brief time; once the blinking stops the drive is ready to use.
NOTE: changing the RAID mode for the Mercury Elite Pro Dual requires an active USB or FireWire connection.
See Section 2.3.2 - “RAID Modes” for more information on each RAID mode that can be used, and how it
differs from the others.
2.3.2 RAID Modes
RAID 0 “Drive Striping” Mode:
The two drives show up as a single large disk with a size equal to the combined capacities of both drives.
RAID 0 is used when speed is the primary objective; it does not provide data redundancy for protection.
The reading and writing of data files is spread across both drives to gain speed by distributing the workload.
This allows for the fastest data transfer rates, but if one drive fails the whole array becomes corrupted. The
data will be lost.
RAID 1 “Drive Mirroring” Mode:
The two drives show up as a single disk with a size equal to the capacity of a single drive from the array.
RAID 1 copies (or “mirrors”) the data from the first drive to the second drive. This is useful when reliability
and redundancy are more important than capacity or maximum speed. When one drive fails, it can be
replaced and the data can be rebuilt automatically from the other functioning drive. See
Section 2.4
for
more details on the drive replacement and rebuild process.
Warning
Changing the RAID mode will destroy the data on the drives. Be sure to back up your data first!
See Section 3.4 for information on proper backup strategies.
Note
Changing the RAID mode for the Mercury Elite Pro Dual requires an active USB or FireWire
connection.
Warning
Drives of identical model and capacity are required for RAID 0 and RAID 1. Always maintain a full
and separate backup of your RAID disks, especially RAID 0 disks.
