Using the Event Monitoring Service (November 1999)

98
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 The segments of
spaces that can be separated
physically on a disk or be on serial
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)
Software that 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
assigns identifiers for the objects.
MIB II (MIB2) An MIB that
defines information about the
system, the network interface
cards, routing information, the
TCP and UDP sockets and their
states, and various statistics
related to error counts. This MIB is
widely adopted and is served by
most IP-addressed devices. Most
system and network resources
managed by EMS HA Monitors are
taken from this MIB.
monitor See resource monitor.
N-P
notification See alert.