MSA 2040 SMU Reference Guide

Glossary 183
masking A volume-mapping setting that specifies no access to that volume by hosts. See also default
mapping and explicit mapping.
master volume A volume that is enabled for snapshots and has an associated snap pool.
MC Management Controller. A processor (located in a controller module) that is responsible for
human-computer interface and computer-computer interfaces, including the WBI, CLI, and
FTP interfaces, and interacts with the Storage Controller. See also EC and SC.
Media Access Control
Address
See MAC address.
metadata Data in the first sectors of a disk drive that stores all disk-, vdisk-, and volume-specific
information including vdisk membership or spare identification, vdisk ownership, volumes
and snapshots in the vdisk, host mapping of volumes, and results of the last media scrub.
MIB Management Information Base. A database used for managing the entities in SNMP.
mount To enable access to a volume from a host OS. Synonyms for this action include present and
map. See also host, map/mapping, and volume.
network port The Ethernet port on a controller module through which its Management Controller is
connected to the network.
network time protocol See NTP.
NTP Network time protocol.
object identifier See OID.
OID Object Identifier. In SNMP, an identifier for an object in a MIB.
orphan data See unwritable cache data.
Partner Firmware
Update
See PFU.
passphrase A user-created password that allows users to manage lock keys in an FDE-capable system.
See also FDE and lock key.
PCBA Printed circuit board assembly.
PFU Partner firmware update. The automatic update of the partner controller when the user
updates firmware on one controller.
PGR Persistent group reservations.
PHY One of two hardware components that form a physical connection between devices in a
SAS network that enables transmission of data.
physical layer See PHY.
point-to-point Fibre Channel Point-to-Point topology, where two ports are directly connected.
POST Power-on self test. Tests that run immediately after a device is powered on.
Power-On Self Test See POST.
power supply unit See PSU.
primary volume The volume that is the source of data in a replication set and that can be mapped to hosts.
For disaster recovery purposes, if the primary volume goes offline, a secondary volume can
be designated as the primary volume. The primary volume exists in a primary vdisk in the
primary (or local) storage system.
proxy volume A virtual volume in the local system that represents a volume in a remote system. Proxy
volumes are used internally by the controllers to perform actions such as transferring
replication data.
PSU Power supply unit. The power supply FRU.
recovery In an active-active configuration, recovery is the act of returning ownership of controller
resources to a controller (which was offline) from its partner controller. The resources include
volumes, cache data, host ID information, and LUNs and WWNs. See also failover.