IBM Enterprise Storage Server 2105 E10, Introduction And Planning Manual

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The LVM maps data between the logical view of storage
space and the physical disk drive module (DDM).
LPAR. See logical partition.
LRU. See least recently used.
LSS. See logical subsystem.
LUN. See logical unit number.
LVM. See logical volume manager.
M
machine level control (MLC). A database that
contains the EC level and configuration of products in
the field.
maintenance analysis procedure (MAP). A hardware
maintenance document that gives an IBM service
representative a step-by-step procedure for tracing a
symptom to the cause of a failure.
management information base (MIB). The physical
and logical characteristics of a system make up a
collection of information called a management
information base (MIB). The individual pieces of
information that comprise an MIB are called MIB objects
and they reside in the SNMP Agent. See
simple network
management protocol.
MAP. See maintenance analysis procedure.
MB. See megabyte.
MCA. See Micro Channel architecture.
mean time between failures (MTBF). (1) A projection
of the time that an individual unit remains functional.
The time is based on averaging the performance, or
projected performance, of a population of statistically
independent units. The units operate under a set of
conditions or assumptions. (2) For a stated period in the
life of a functional unit, the mean value of the lengths of
time between consecutive failures under stated
conditions. (I) (A)
medium. For a storage facility, the disk surface on
which data is stored.
megabyte (MB). (1) For processor storage, real and
virtual storage, and channel volume, 2
20
or 1 048 576
bytes. (2) For disk storage capacity and
communications volume, 1 000 000 bytes.
MES. See miscellaneous equipment system.
MIB. See management information base.
Micro Channel architecture (MCA). The rules that
define how subsystems and adapters use the Micro
Channel bus in a computer. The architecture defines the
services that each subsystem can or must provide.
mirrored pair. Two units that contain the same data.
The system refers to them as one entity.
mirroring. In the AS/400 host systems, the process of
writing the same data to two disk units within the same
auxiliary storage pool at the same time.
miscellaneous equipmet specification.
MLC. See
machine level control.
mobile service terminal (MoST). The mobile terminal
used by IBM service personnel.
MoST. See mobile service terminal.
MTBF. See mean time between failures.
multiple virtual storage (MVS). Consisting of
MVS/System Product Version 1 and MVS/370 Data
Facility Product operating on an IBM System/370
processor.
MVS. See multiple virtual storage.
N
node. The unit that is connected in a fibre-channel
network. An ESS is a node in a fibre-channel network.
non-RAID. A collection of disk drives in a non-RAID
group or array.
non-removable medium. A recording media that you
cannot add to or remove from a storage device.
non-retentive data. Data that the control program can
easily recreate in the event it is lost. The control
program may cache non-retentive write data in volatile
memory.
nonvolatile storage (NVS). (1) Typically refers to
nonvolatile memory on a processor rather than a
nonvolatile storage device. On a storage facility,
nonvolatile storage is used to store active write data to
avoid data loss in the event of a power loss. (2) A
storage device whose contents are not lost when power
is cut off.
NVS. See nonvolatile storage.
O
OEMI. See original equipment manufacturer’s
information.
open system. A system whose characteristics comply
with standards made available throughout the industry
and that therefore can be connected to other systems
complying with the same standards.
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ESS Introduction and Planning