Glossary 183memory — An area in your system that stores basic system data. A system can containseveral different forms of memory, such as integrated memory (ROM and RAM) andadd-in memory modules (DIMMs).MHz — Megahertz.mirroring — A type of data redundancy in which a set of physical drives stores dataand one or more sets of additional drives stores duplicate copies of the data. Mirroringfunctionality is provided by software. See also guarding, integrated mirroring, striping,and RAID.mm — Millimeter(s).ms — Millisecond(s).MS-DOS® — Microsoft Disk Operating System.NAS — Network Attached Storage. NAS is one of the concepts used for implementingshared 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 asystem to allow connection to a network.NMI — Nonmaskable interrupt. A device sends an NMI to signal the processor abouthardware errors.ns — Nanosecond(s).NTFS — The NT File System option in the Windows 2000 operating system.NVRAM — Nonvolatile random-access memory. Memory that does not lose itscontents 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.partition — You can divide a hard drive into multiple physical sections calledpartitions 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-busimplementation.PDU — Power distribution unit. A power source with multiple power outlets thatprovides electrical power to servers and storage systems in a rack.peripheral — An internal or external device, such as a diskette drive or keyboard,connected to a system.PGA — Pin grid array. A type of processor socket that allows you to remove theprocessor chip.
