HP StorageWorks 200 Storage Virtualization System site preparation guide (AE071-96003, October 2006)

Glossary
ACP system control processor. On some XP models, such as the XP12000, the ACP
handles the passing of data between the cache and the physical drives. On
other XP models, such as the SVS200, this function is ha ndled by the disk
adapter on the MIX board.
AL Arbitrated loop.
AL-PA Arbitrated loop physical address.
allocation The ratio of allocated storage capacity versus total capacity as a percentage.
“Allocated storage” refers to those LDEVs that have paths assigned to them.
The allocated storage capacity is the sum of the storage of these LDEVs. Total
capacity refers to the sum of the capacity of all LDEVs on the system.
system group A group of 4 or 8 physical hard disk drives (HDDs) installed in an XP system
and assigned a common RAID level. RAID1 system groups consist of 4 (2D+2D)
or 8 HDDs (4D+4D). R A ID5 system groups include a parity disk b ut also consist
of 4 (3D+1P) or 8 HDDs (7D+1P). All RAID6 system groups are made up of 8
HDDs (6D+2P).
ASE Application System Engineer.
BC The H P StorageWorks Business Copy XP software program, which enab les you
to maintain up to nine internal copies of logical volumes on the system.
C-Track The HP Storage Works Continuous Track XP software program, which detects
internal hardware component problems on a system and automatically reports
them to the HP STC.
Continuous Access The HP StorageWorks Continuous Access program, which enables you to
replicate data stored on a local s ystem to a remote s ystem.
cache Very high speed m em o ry that is used to speed I/O transaction time. All reads
and writes to the XP system family are sent to the ca che. The data is buffered
there until the transfer to/from physical disks (with slower data throughput)
is complete.
The benefit of cache memory is that it speeds I/O throughput to the application.
Thelargerthecachesize,thegreatertheamountofdatabufferingthatcan
occur and the greater throughput to the applications.
XP systems support a range of cache memor y. In the event of power loss, battery
power holds up the contents of cache for up to 36 hours.
CE Customer engineer.
channel adap ter
(CHA)
The channel adapter (CHA) provides the interface between the system and the
external host system. O ccasionally this term is used synonymously with the term
channel host interface processor (CHIP).
channel host in-
terface processor
(CHIP)
Synonymous with the term channel adapter (CHA).
channel processor
(CHP)
The processors located on the channel adapter (CHA). Synonymo
us with CHIP.
command device A volume on the system that accepts Continuous Access or Business Copy
control operations which are then executed by the system.
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