Using EMS HA Monitors

Glossary 81
Glossary
A-H
alert An event. A message sent to warn
a user or application when certain
conditions are met.
client The application that creates or
cancels requests to monitor particular
resources. The consumer of a resource
status message. A user of the Resource
Monitor framework. This user may
browse resources, request status, and
make requests to have resources
monitored. Examples are MC/
ServiceGuard as it starts a package or
the SAM interface to EMS.
event An alert.
I-K
ITO HP OpenView IT/Operations,
formerly known as OperationsCenter.
L
logical extent The basic allocation unit
for a logical volume is called a logical
extent. For mirrored logical volumes,
either two or three physical extents are
mapped for each logical extent,
depending on whether you are using 2-
way or 3-way mirroring.
logical volume A collection of disk
space from one or more disks. Each
collection appears to the operating
system as a single disk. Like disks,
logical volumes can be used to hold file
systems, raw data areas, dump areas, or
swap areas. Unlike disks, logical
volumes can be given a size when they
are created, and a logical volume can
later be expanded or reduced. Also,
logical volumes can be spread over
multiple disks.
LUN (Logical Unit Numbers) A logical
disk device composed of one or more
physical disk mechanisms, typically
configured into a RAID level.
LVM (Logical Volume Manager)
Manages disks in volume groups, and
allows you to create logical and physical
volume groupings.
M
MIB (Management Information Base).
A document that describes objects to be
managed. A MIB is created using a
grammar defined in “Structure of
Management Information” (SMI)
format. This grammar concisely defines
the objects being managed, the data
types these objects take, descriptions of
how the objects can be used, whether
the objects are read-only or read-write,
and identifiers for the objects.