HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Maintenance and Service Guide (EK-G80MS-SA. C01, March 2005)

Glossary
266 HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software
Maintenance and Service Guide
dual data link
See DDL.
dual-redundant configuration
An array controller configuration consisting of two active controllers operating as a single
controller. If one controller fails, the other controller assumes control of the failing controller
devices.
ECB
External Cache Battery. The unit that supplies backup power to the cache module in the event
the primary power source fails or is interrupted.
EIA
Electronic Industries Association. EIA is a standards organization specializing in the electrical
and functional characteristics of interface equipment.
EMU
Environmental Monitoring Unit. A unit that provides increased protection against catastrophic
failures. Some subsystem enclosures include an EMU which works with the array controller to
detect conditions such as failed power supplies, failed blowers, elevated temperatures, and
external air sense faults. The EMU also controls certain rack hardware including DOC chips,
alarms, and fan speeds.
environmental monitoring unit
See EMU.
extended subsystem
A subsystem in which one or two enclosures are connected to the primary enclosure.
external cache battery
See ECB.
failedset
A group of disk drives that have been removed from RAIDsets due to a failure or a manual
removal. Disk drives in the failedset should be considered defective and should be tested and
repaired before being placed back into the spareset. See also spareset.
failover
The process that takes place when one controller in a dual-redundant configuration assumes the
workload of a failed companion controller. Failover continues until the failed controller is
repaired or replaced. See also failback.
fault management utility
See FMU.
fiber
A fiber or optical strand. Spelled fibre in Fibre Channel.