OWC
Rack Pro mini-SAS
Introduction
3
1.6 About RAID Modes
The Mercury Rack Pro mini-SAS does not ship with built-in RAID capabilities,
however many mini-SAS PCIe cards have RAID controller functionality built into
them. The number and type of RAID modes available are entirely dependent upon
the card you use. Please consult the manufacturer’s documentation for more
information about the capabilities of your specific card. The information below
describes a few of the more commonly used RAID modes.
RAID 0 (“Drive Striping”)
— The drives appear as one large volume with a size
equal to the combined capacities of all the drives in the array. RAID 0 is used
when speed is the primary objective; it does not provide data redundancy. Data
is distributed across two or more drives and is written and read without pausing to
check parity information. This greatly improves the speed but if one drive fails the
whole array can become corrupted and data will be lost.
Always maintain a backup of your data!
RAID 1 (“Drive Mirroring”)
— The drives appear as one volume with a size
equal to the capacity of a single installed drive. RAID 1 copies (or “mirrors”) a set
of data from the first drive to the second drive. This is useful when reliability and
redundancy are more important than capacity or speed. When one drive fails, it
can be replaced and the data will be rebuilt.
RAID 10 (“Mirrored Stripes”)
— The drives appear as one volume with a size
equal to the combined capacities of half of the drives in the array. RAID 10 uses a
combination of striped and mirrored volumes. If one drive fails, it can be replaced
and the data rebuilt.
RAID 5 (“Stripe with Parity”)
— The drives appear as one volume with a size
equal to the combined capacities of all drives in the array, minus one drive. RAID 5
uses block-level striping with parity data distributed across all disks. It provides a
good balance between performance and data integrity. If one drive fails, it can be
replaced and the data rebuilt.
