13 raid, Raid types – HP 3PAR Operating System Software Licenses User Manual
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13 RAID
RAID is a storage functionality that distributes data in units called chunklets across physical disks
in order to create redundancy and therefore increase the stability of your stored data. On the HP
3PAR StoreServ 7000 Storage system, a chunklet is 1 GB.
RAID is one of the parameters of a CPG, the storage pool from which volumes allocate storage
space. You can set the RAID type, along with other parameters, when you create a CPG, and you
can also modify an existing CPG’s RAID.
RAID Types
HP 3PAR storage systems support the following types of RAID:
•
RAID 0: Data is striped across rows of chunklets on different physical disks.
RAID 0 improves performance but provides no fault-tolerance.
•
RAID 10 (RAID 1): 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 could be located in different drive magazines or different
drive cages.
A RAID 1 set can function with the loss of all but one of the chunklets in the set.
•
RAID 50 (RAID 5): Data is striped across rows of RAID 5 sets. A RAID 5 set, or
set, is
made up of at least three chunklets. Each RAID 5 set contains a total of two chunklets of space
for data and one chunklet of space for parity. The chunklets in each RAID 5 set are distributed
across different physical disks, which could be located in different drive magazines or different
drive cages.
A RAID 5 set can function with the loss of any one of the chunklets in the set.
•
RAID Multi-parity (MP) (RAID 6): Data is striped across rows of RAID MP sets. A RAID MP set,
or double-parity set, is made up of at least 8 chunklets. Each RAID MP set contains a total of
6 chunklets of space for data and 2 chunklets of space for parity. The chunklets in each RAID
MP set are distributed across different physical disks, which could be located in different drive
magazines or different drive cages.
A RAID MP set can function with the loss of any two of the chunklets in the set.
For more information about the implementation of RAID in HP 3PAR storage systems, see the HP
3PAR StoreServ Storage Concepts Guide. To access this document, go to the HP 3PAR StoreServ
Storage site and click the Support link for your product:
RAID Types
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