HP XP P9500 Storage - Manual (Page 225)

Glossary
This glossary defines the special terms used in this document. Click the letter links below
to navigate.
2DC two-data-center. Refers to the local and remote sites, or data centers, in which Continuous Access
Synchronous (Cnt Ac-S) and Continuous Access Journal (Cnt Ac-J) combine to form a remote
replication configuration.
In a 2DC configuration, data is copied from a Cnt Ac-S primary volume at the local site to the
Cnt Ac-J master journal volume at an intermediate site, then replicated to the Cnt Ac-J secondary
volume at the remote site. Since this configuration side-steps the Cnt Ac-S secondary volume at
the intermediate site, the intermediate site is not considered a data center.
3DC three-data-center. Refers to the local, intermediate, and remote sites, or data centers, in which
Continuous Access Synchronous and Continuous Access Journal combine to form a remote
replication configuration.
In a 3DC configuration, data is copied from a local site to an intermediate site and then, to a
remote site (3DC cascade configuration), or from a local site to two separate remote sites (3DC
multi-target configuration).
access attribute The setting on a logical volume (mainframe or open-systems) that determines whether hosts can
read and/or write to the volume.
APLB active path load balancing
array See disk array
audit log Files that store a history of the operations performed from Remote Web Console and the commands
that the storage system received from hosts, and data encryption operations.
bind mode In bind mode the Cache Residency extents are used to hold read and write data for specific
extent(s) on volume(s). Data written to the Cache Residency bind area is not de-staged to the
drives. For bind mode, all targeted read and write data is transferred at host data transfer speed.
blade A computer module, generally a single circuit board, used mostly in servers.
cache logical
partition (CLPR) Consists of virtual cache memory that is set up to be allocated to different hosts in contention for
cache memory.
capacity The amount of data storage space available on a physical storage device, usually measured in
bytes (MB, GB, TB, etc.).
CHA See channel adapter (CHA).
CHAP challenge handshake authentication protocol
CLPR cache logical partition
cluster Multiple-storage servers working together to respond to multiple read and write requests.
command device A dedicated logical volume used only by RAID Manager to interface with the storage system.
Can be shared by several hosts.
controller The component in a storage system that manages all storage functions. It is analogous to a
computer and contains a processors, I/O devices, RAM, power supplies, cooling fans, and other
sub-components as needed to support the operation of the storage system.
copy pair A pair of volumes in which one volume contains original data and the other volume contains the
copy of the original. Copy operations can be synchronous or asynchronous, and the volumes of
the copy pair can be located in the same storage system (local copy) or in different storage
systems (remote copy).
A copy pair can also be called a volume pair, or just pair.
copy-on-write Point-in-time snapshot copy of any data volume within a storage system. Copy-on-write snapshots
only store changed data blocks, therefore the amount of storage capacity required for each copy
is substantially smaller than the source volume.
COW copy-on-write
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