HP XP Continuous Access Software - Manual (Page 401)

Glossary 401
Glossary
ACA HP StorageWorks Asynchronous Continuous Access XP.
ACP Array Control Processor. The ACP handles passing data between cache and
the physical drives. ACPs work in pairs. In the event of an ACP failure, the
redundant ACP takes control. Both ACPs work together sharing the load.
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. Allocated storage capacity is the sum of the storage of these LDEVs.
Total capacity is the sum of the capacity of all LDEVs on the array.
array group A group of 4 or 8 physical hard disk drives (HDDs) installed in an XP disk
array and assigned a common RAID level. RAID1 array groups consist of 4
(2D+2D) or 8 HDDs (4D+4D). RAID5 array groups include a parity disk
but also consist of 4 (3D+1P) or 8 HDDs (7D+1P). All RAID6 array groups
are made up of 8 HDDs (6D+2P).
AL-PA Arbitrated loop physical address.
BC HP StorageWorks Business Copy XP. BC lets you maintain up to nine local
copies of logical volumes on the disk array.
CA HP StorageWorks Continuous Access XP. CA lets you create and maintain
duplicate copies of local logical volumes on a remote disk array.
cache Very high speed memory used to speed I/O transaction time. All reads and
writes to the array are sent to the cache. The data is buffered there until the
transfer to/from physical disks (with slower data throughput) is complete.
Cache memory speeds I/O throughput to the application.
CE Customer engineer.