Hitachi Data Systems
Consistency Groups
A software copy technique of suspending multiple volumes at the same time.
Control Frame
The Disk Controller or control frame, is the center cabinet of the Lightning 9900™ Series system, housing the channel switch, cache, power supplies, batteries, and host interface cards.
CORA (Cost of Risk Analysis)
CORA is a unique,
Cost Benefit Analysis
A major benefit of the CORA process is the Cost Benefit Analysis where each action to mitigate risk is evaluated in terms of cost and return on investment. See also CORA.
CPU
CPU is an acronym for Central Processing Unit. Can refer to either a processor chip such as Sun’s SPARC™ or Intel’s Pentium®, or to a processor chip or chips and support circuitry on a CPU board.
CSW
Cache Switch. A specially designed crossbar switch for use in the Lightning 9900™ Series. They are not Fibre Channel switches.
CTQ
DA
The Data Adapter resides on the CHT and connects the cache boards to the front end.
DASD
An IBM® coined anacronym that means Direct Access Storage Device, i.e. a disk drive.
Data availability
Data availability refers to the degree to which a computer system is capable of providing data to its users. See also Availability.
Data Copy
A term that refers to both remote copy, data duplication, and data migration.
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