IBM TotalStorage DS4300 Turbo, Installation, User'S, And Maintenance Manual

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partition is the same size as the physical partitions in its
volume group. Unless the logical volume of which it is a
part is mirrored, each logical partition corresponds to,
and its contents are stored on, a single physical
partition. (3) One to three physical partitions (copies).
The number of logical partitions within a logical volume
is variable.
logical unit number (LUN). An identifier used on a
small computer system interface (SCSI) bus to
distinguish among up to eight devices (logical units) with
the same SCSI ID.
loop address. The unique ID of a node in
fibre-channel loop topology sometimes referred to as a
loop ID.
loop group. A collection of storage area network
(SAN) devices that are interconnected serially in a
single loop circuit.
loop port. A node port (N_port) or fabric port (F_port)
that supports arbitrated loop functions associated with
an arbitrated loop topology.
LPAR. See logical partition .
LUN. See logical unit number .
MAC. See medium access control .
management information base (MIB). The
information that is on an agent. It is an abstraction of
configuration and status information.
man pages. In UNIX-based operating systems, online
documentation for operating system commands,
subroutines, system calls, file formats, special files,
stand-alone utilities, and miscellaneous facilities.
Invoked by the man command.
MCA. See micro channel architecture .
media scan. A media scan is a background process
that runs on all logical drives in the storage subsystem
for which it has been enabled, providing error detection
on the drive media. The media scan process scans all
logical drive data to verify that it can be accessed, and
optionally scans the logical drive redundancy
information.
medium access control (MAC). In local area
networks (LANs), the sublayer of the data link control
layer that supports medium-dependent functions and
uses the services of the physical layer to provide
services to the logical link control sublayer. The MAC
sublayer includes the method of determining when a
device has access to the transmission medium.
Metro Mirroring. This term is used to refer to a
remote logical drive mirror pair which is set up with
synchronous write mode. See also remote mirroring ,
Global Mirroring .
MIB. See management information base .
micro channel architecture (MCA). Hardware that is
used for PS/2 Model 50 computers and above to
provide better growth potential and performance
characteristics when compared with the original
personal computer design.
Microsoft Cluster Server (MSCS). MSCS, a feature
of Windows NT Server (Enterprise Edition), supports the
connection of two servers into a cluster for higher
availability and easier manageability. MSCS can
automatically detect and recover from server or
application failures. It can also be used to balance
server workload and provide for planned maintenance.
mini hub. An interface card or port device that
receives short-wave fiber channel GBICs or SFPs.
These devices enable redundant fibre channel
connections from the host computers, either directly or
through a fibre channel switch or managed hub, over
optical fiber cables to the DS4000 Storage Server
controllers. Each DS4000 controller is responsible for
two mini hubs. Each mini hub has two ports. Four host
ports (two on each controller) provide a cluster solution
without use of a switch. Two host-side mini hubs are
shipped as standard. See also host port, gigabit
interface converter (GBIC), small form-factor pluggable
(SFP) .
mirroring. A fault-tolerance technique in which
information on a hard disk is duplicated on additional
hard disks. See also remote mirroring .
model. The model identification that is assigned to a
device by its manufacturer.
MSCS. See Microsoft Cluster Server .
network management station (NMS). In the Simple
Network Management Protocol (SNMP), a station that
runs management application programs that monitor
and control network elements.
NMI. See non-maskable interrupt .
NMS. See network management station .
non-maskable interrupt (NMI). A hardware interrupt
that another service request cannot overrule (mask). An
NMI bypasses and takes priority over interrupt requests
generated by software, the keyboard, and other such
devices and is issued to the microprocessor only in
disastrous circumstances, such as severe memory
errors or impending power failures.
node. A physical device that allows for the
transmission of data within a network.
node port (N_port). A fibre-channel defined hardware
entity that performs data communications over the
fibre-channel link. It is identifiable by a unique worldwide
name. It can act as an originator or a responder.
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IBM TotalStorage DS4300 Fibre Channel Storage Subsystem: Installation, User’s, and Maintenance Guide