User Guide

Glossary 195
memory — An area in your system that stores basic system data. A system can contain
several different forms of memory, such as integrated memory (ROM and RAM) and
add-in memory modules (DIMMs).
memory key — A portable flash memory storage device integrated with a USB
connector.
MHz — Megahertz.
mirroring — A type of data redundancy applicable to hard drives or system memory.
When applied to hard drives, a set of physical drives stores data and one or more sets
of additional drives stores duplicate copies of the data. Mirroring functionality is
provided by software. See also striping and RAID. When applied to system memory,
data in one set of memory modules is duplicated in an identical set of memory
modules.
mm — Millimeter(s).
ms — Millisecond(s).
NAS — Network Attached Storage. NAS is one of the concepts used for implementing
shared storage on a network. NAS systems have their own operating systems,
integrated hardware, and software that are optimized to serve specific storage needs.
NIC — Network interface controller. A device that is installed or integrated in a
system to allow connection to a network.
NMI — Nonmaskable interrupt. A device sends an NMI to signal the processor about
hardware errors.
ns — Nanosecond(s).
NVRAM — Nonvolatile random-access memory. Memory that does not lose its
contents when you turn off your system. NVRAM is used for maintaining the date,
time, and system configuration information.
parity — Redundant information that is associated with a block of data.
parity stripe — In RAID arrays, the parity-striped hard drive of a set of striped hard
drives contains parity data that enable data recovery in the event that one of the other
hard drives fails.
partition — You can divide a hard drive into multiple physical sections called
partitions with the fdisk command. Each partition can contain multiple logical drives.
You must format each logical drive with the format command.
PCI — Peripheral Component Interconnect. A standard for local-bus
implementation.
PCIe — PCI Express. An improved PCI expansion bus technology that uses one or
multiple full-duplex serial data lines to interface between the CPU and the expansion
card and which greatly increases data bandwidth.