HP StorageWorks HSG80 Array Controller V8.7 Maintenance And Service Manual page 170

Glossary
dual data link
See DDL
dual-redundant configuration
A 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 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
ESD
Electrostatic Discharge. The discharge of potentially harmful static electrical voltage as a
result of improper grounding.
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
Glossary–4 HSG80 Array Controller V8.7 Maintenance and Service Guide