Raid Types; Raid 0; Raid 1 And 10 - HP 3PAR StoreServ 7200 2-node Manual

failures. When the destination logical disks become available again, the system automatically
writes the preserved data from the preserved data logical disks to the destination logical disks.
Administration volume logical disks provide storage space for the admin volume, a single
volume created on each system during installation. The admin volume is used to store system
administrative data such as the system event log.

RAID Types

The 3PAR storage system supports the following RAID types:

RAID 0

RAID 10 (RAID 1)
RAID 50 (RAID 5)
RAID Multi-parity (MP)
RAID 0
On a RAID 0 logical disk, data is striped across rows of chunklets on different physical disks. The
number of chunklets in a RAID 0 set is known as the set size, which is always 1 for a RAID 0 logical
disk. The number of sets in a row is known as the row size. The system accesses data from a RAID
0 logical disk in step sizes, where the step size is the number of contiguous bytes that the system
accesses before moving on to the next chunklet. A RAID 0 logical disk improves performance but
provides no fault-tolerance.
Figure 3 (page 35)
Figure 3 Data Striped Across Chunklets on a RAID 0 Logical Disk

RAID 1 and 10

On a RAID 10 logical disk, data is striped across RAID 1 (or mirrored) sets. A RAID 1 set is made
up of two or more chunklets that contain the same data. The chunklets in each set are distributed
across different physical disks, which may be located in different drive magazines or even different
drive cages. The number of chunklets in a RAID 1 set is the set size (or mirror depth). The number
of sets in each row is the row size. The maximum row size is 40. The system accesses data from
a RAID 10 logical disk in step sizes. A step size is the number of contiguous bytes that the system
accesses before moving on to the next chunklet. A RAID 1 set can function with the loss of all but
one of the chunklets in the set.
Figure 4 (page 36)
rows:
shows a RAID 0 logical disk with a set size of 1 and a row size of 3:
shows a RAID 10 logical disk with a set size of 2 and a row size of 3 in two
RAID Types 35