Glossary – HP XP Racks User Manual

Page 93

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Glossary

BC

P9000 or XP Business Copy. An HP application that provides volume-level, point-in-time copies
in the disk array.

CLPR

Cache logical partition.

Cnt Ac-J

P9000 or XP Continuous Access Journal software.

Cnt Ac-S

P9000 or XP Continuous Access Synchronous software.

command device

A volume in the disk array that accepts Continuous Access, Business Copy, or P9000 for Business
Continuity Manager control operations, which are then executed by the array.

CTGID

Consistency group ID. The group identifier used to identify a group of volumes in the HP
StorageWorks P9500 Disk Array being replicated using an asynchronous technology. The
consistency group feature guarantees the sequencing of updates to the secondary volumes.

CU

Control Unit. Used to organize the storage space attached to the disk controller (DKC). You can
group similarly configured logical devices (LDEVs) with unique control unit images (CUs). CUs
are numbered sequentially. The disk array supports a certain number of CUs, depending on the
disk array model. Each CU can manage multiple LDEVs; therefore, both the CU number and the
LDEV number are required to identify an LDEV.

emulation mode

The LDEVs associated with each RAID group are assigned an emulation mode that makes them
operate like OPEN system disk drives. The emulation mode determines the size of an LDEV or
volume.

OPEN-V: User-defined custom size

3390-3/3R: 2.838 GB

3390-9: 8.514 GB

3390-L: 27.844 GB

3390-M: 55.689 GB

3380-3 2.377 GB

failover

The process that occurs when one device assumes the workload of a failed companion device.
Failovers can be planned or unplanned.

fence level

A method of setting rejection of P9000 or XP Continuous Access write I/O requests from the host
according to the condition of mirroring consistency.

Fibre Channel

A data transfer architecture designed for mass storage devices and other peripheral devices that
require high bandwidth.

LDKC

Logical disk controller.

LUN

Logical unit number. A LUN results from mapping a logical unit number, port ID, and LDEV ID to
a RAID group. The size of the LUN is determined by the emulation mode of the LDEV and the
number of LDEVs associated with the LUN.

LUSE

Logical Unit Size Expansion. The LUSE feature is available when the HP StorageWorks LUN
Manager product is installed, and allows a LUN, normally associated with only a single LDEV,
to be associated with 1 to 36 LDEVs. Essentially, LUSE makes it possible for applications to access
a single large pool of storage.

MCU

Main control unit.

OPEN-

x

A general term describing any of the supported OPEN emulation modes (for example, OPEN-E).
There are two types of OPEN-x devices: legacy OPEN-x devices with a fixed size (such as OPEN-3,
OPEN-8, OPEN-9, and OPEN-E), and OPEN-V, which has a variable size and is a CVS-based
volume.

P-VOL

Primary volume.

parity group

A set of hard disk drives that have the same capacity and that are treated as one group. A parity
group contains both user data and parity information, which enables user data to be accessed
if one or more drives in the group is not available.

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