User guide

OWC Mercury Elite-AL Pro Qx2 Chapter 1 - Introduction
1.6.4 Disk Mirroring with Striping (RAID 10) (also known as RAID 1+0) (4 Drives)
The drives show up as one volume, but only 50% of the total capacity can be used,
depending on the drive with the smallest capacity. RAID 10 creates an exact copy (or
“mirror”) of a set of data but also uses a RAID 0 Stripe for speed. When one hard drive
fails, it can be replaced and the data rebuilt automatically.
1.6.5 Disk Striping with parity (RAID 5) (3 or 4 Drives)
The drives show up as one volume, but the total capacity, depending on the drive with
the smallest capacity, is the combined size minus the size of one drive. RAID 5 uses
block level striping with parity data distributed across all member disks and therefore
provides the perfect balance between high performance and data integrity. When one
hard drive fails, it can be replaced and the data rebuilt automatically.
Spare Drive
When 3 hard drives plus 1 spare drive are used, the total capacity will be only as large
as two drives. When one drive fails, the data will be rebuilt immediately by using the
spare drive, rather than waiting for the faulty drive to be replaced.
NOTE:
Hard drives of identical capacities are required, and the it is highly recommended to
also use hard drives with identical rmware. OWC recommends having an extra drive
of the same capacity and rmware already purchased and ready to use in case of drive
mechanism failure
1.6.6 Changing the RAID mode
Changing the RAID setup will require you to reformat the hard drives. Make sure that
you have backed up your data before proceeding!
1. Turn o the power and then set the RAID selector switch to the new position.
2. Turn on the power, erase the old partition, create a new one and then reformat the
drives. Instructions for this are in Chapter 3.
3 Drives
4 Drives
3 Drives
+ 1 Spare
Storage Capacity
Data Safety
Performance
Storage Capacity
Data Safety
Performance
Storage Capacity
Data Safety
Performance
Storage Capacity
Data Safety
Performance