HP StorageWorks HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide (EK-G80TS-SA. C01, March 2005)

Glossary
282 HSG60 and HSG80 Array Controller and Array Controller Software Troubleshooting Guide
EMU
Environmental monitoring unit. A unit that provides increased protection against
catastrophic failures. Some subsystem enclosures include an EMU that 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.
F_Port
A port in a fabric where an N_Port or NL_Port may attach.
fabric
A group of interconnections between ports that includes a fabric element.
failback
The process of restoring data access to the newly-restored controller in a dual-redundant
controller configuration.
See also failover.
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 after 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.