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Fault Tolerance RAID

Fault Tolerance RAID
Descriptions

Descriptions

Keeps data available and server running while a failed drive is being replaced; several fault tolerance
configurations are supported including but not limited to (see P2000 G3 QuickSpecs for details):

RAID 0 (striping)

RAID 0 (striping) provides no extra data protection. Data is striped across all drives in the array to
increase performance. RAID 0 requires a minimum of one drive.
RAID 1 (mirroring)

RAID 1 (mirroring)

RAID 1 (mirroring) protects against failure of one drive. Data is duplicated on a pair of drives.
RAID 1 requires a minimum of two drives. Also see the Advanced Pack Mirror Splitting and
Combining feature.
RAID 1+0 (mirroring and striping)

RAID 1+0 (mirroring and striping)

RAID 1+0 (mirroring and striping) protects against failure of one drive (and failure of particular
multiple drives). RAID 1+0 is a nested RAID method that uses RAID 0 striping across RAID 1
arrays to provide performance and protection. RAID 1+0 requires a minimum of four drives. Also
see the Advanced Pack Mirror Splitting and Combining feature.
RAID 5 (distributed data guarding)

RAID 5 (distributed data guarding)

RAID 5 (distributed data guarding) protects against failure of one drive. Data protection is
provided by parity data distributed across all the drives. When a physical drive fails, data that was
on the failed drive can be calculated from the remaining parity data and user data on the other
drives in the array. This recovered data is usually written to an online spare drive through a
process called a rebuild. RAID 5 requires a minimum of three drives.
RAID 6 with ADG

RAID 6 with ADG

RAID 6 with ADG (Advanced Data Guarding): This is the highest level of fault tolerance. It
allocates two sets of parity data across drives and allows simultaneous write operations. This level
of fault tolerance can withstand two simultaneous drive failures without downtime or data loss.
RAID 50 (RAID 5+0)

RAID 50 (RAID 5+0)

RAID 50 (RAID 5+0) protects against failure of one drive (and failure of particular multiple
drives). RAID 50 is a nested RAID method that uses RAID 0 striping across RAID 5 arrays. RAID 50
tolerates one drive failure in each spanned array without loss of data. RAID 50 requires less
rebuild time than single RAID 5 arrays RAID 50 requires a minimum of six drives.
RAID 60 (RAID 6+0)

RAID 60 (RAID 6+0)

RAID 60 (RAID 6+0) allows administrators to split the RAID 6 storage across multiple external
boxes. RAID 60 requires a minimum of eight drives. RAID 60 is a nested RAID method that uses
RAID 0 block-level striping across multiple RAID 6 arrays with dual distributed parity. With the
inclusion of dual parity, RAID 60 will tolerate the failure of two disks in each spanned array without
loss of data.

NOTE:

NOTE: See Enclosure QuickSpecs for descriptions of RAID levels specific to the HP P2000 Modular
Smart Array Systems

Fault Recovery

Minimizes downtime, reconstructs data, and facilitates a quick recovery from drive failure

Recovery ROM:

Recovery ROM: This feature provides unique redundancy that protects from a ROM image
corruption. A new version of firmware can be flashed to the ROM while the controller maintains
the last known working version of firmware. If the firmware becomes corrupt, the controller will
revert back to the previous version of firmware and continue operating. This reduces the risk of
flashing firmware to the controller.
On-Line Spares:

On-Line Spares:

On-Line Spares: There is no limit to the number of spare drives that can be installed prior to drive
failure. If a failure occurs, recovery begins with an On-Line Spare and data is reconstructed
automatically.

Ease of Use

Consistency and Upgradeability make the Smart Array family unique in the industry:

GUI based configuration, management and diagnostic software tools
Common data format between generations of products
Data migration between servers and external Modular Smart Array enclosures

QuickSpecs

HP Smart Array P711m Controller

Standard Features

DA - 14035 Worldwide — Version 3 — July 1, 2011

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