Dell PowerEdge 1950: Glossary

Glossary

This section defines or identifies technical terms,

BIOS — Basic input/output system. Your system’s BIOS

abbreviations, and acronyms used in your system

contains programs stored on a flash memory chip. The

documents.

BIOS controls the following:

• Communications between the processor and peripheral

devices

A — Ampere(s).

• Miscellaneous functions, such as system messages

AC — Alternating current.

bit — The smallest unit of information interpreted by your

system.

ACPI — Advanced Configuration and Power Interface. A

standard interface for enabling the operating system to

blade — A module that contains a processor, memory, and a

direct configuration and power management.

hard drive. The modules are mounted into a chassis that

includes power supplies and fans.

ambient temperature — The temperature of the area or

room where the system is located.

BMC — Baseboard management controller.

ANSI — American National Standards Institute. The

boot routine — A program that clears all memory,

primary organization for developing technology standards

initializes devices, and loads the operating system when you

in the U.S.

start your system. Unless the operating system fails to

respond, you can reboot (also called warm boot) your

application — Software designed to help you perform a

system by pressing <Ctrl><Alt><Del>. Otherwise, you

specific task or series of tasks. Applications run from the

must restart the system by pressing the reset button or by

operating system.

turning the system off and then back on.

ASCII — American Standard Code for Information

bootable diskette — A diskette that is used to start your

Interchange.

system if the system will not boot from the hard drive.

asset tag — An individual code assigned to a system,

BTU — British thermal unit.

usually by an administrator, for security or tracking

purposes.

bus — An information pathway between the components of

a system. Your system contains an expansion bus that

backup — A copy of a program or data file. As a

allows the processor to communicate with controllers for

precaution, back up your system’s hard drive on a regular

the peripheral devices connected to the system. Your system

basis. Before making a change to the configuration of your

also contains an address bus and a data bus for

system, back up important start-up files from your operating

communications between the processor and RAM.

system.

C — Celsius.

backup battery — A battery that maintains system

configuration, date, and time information in a special

cache — A fast storage area that keeps a copy of data or

section of memory when the system is turned off.

instructions for quick data retrieval. When a program makes

a request to a disk drive for data that is in the cache, the

disk-cache utility can retrieve the data from RAM faster

than from the disk drive.

Glossary 147

CD — Compact disc. CD drives use optical technology to

DIMM — Dual in-line memory module. See also memory

read data from CDs.

module.

cm — Centimeter(s).

DIN — Deutsche Industrie Norm.

cmos — Complementary metal-oxide semiconductor.

directory — Directories help keep related files organized

on a disk in a hierarchical, “inverted tree” structure. Each

component — As they relate to DMI, components include

disk has a “root” directory. Additional directories that

operating systems, computer systems, expansion cards, and

branch off the root directory are called subdirectories.

peripherals that are compatible with DMI. Each component

Subdirectories may contain additional directories branching

is made up of groups and attributes that are defined as

off them.

relevant to that component.

DMA — Direct memory access. A DMA channel allows

COMn — The device names for the serial ports on your

certain types of data transfer between RAM and a device to

system.

bypass the processor.

control panel — The part of the system that contains

DMI — Desktop Management Interface. DMI enables the

indicators and controls, such as the power button and power

management of your system’s software and hardware by

indicator.

collecting information about the system’s components, such

controller — A chip that controls the transfer of data

as the operating system, memory, peripherals, expansion

between the processor and memory or between the

cards, and asset tag.

processor and a peripheral.

DNS — Domain Name System. A method of translating

conventional memory — The first 640 KB of RAM.

Internet domain names, such as www.dell.com, into IP

Conventional memory is found in all systems. Unless they

addresses, such as 143.166.83.200.

®

are specially designed, MS-DOS

programs are limited to

DRAM — Dynamic random-access memory. A system’s

running in conventional memory.

RAM is usually made up entirely of DRAM chips.

coprocessor — A chip that relieves the system’s processor

DVD — Digital versatile disc.

of specific processing tasks. A math coprocessor, for

example, handles numeric processing.

ECC — Error checking and correction.

CPU — Central processing unit. See processor.

EEPROM — Electronically erasable programmable read-

only memory.

DC — Direct current.

EMC — Electromagnetic compatibility.

DDR — Double-data rate. A technology in memory

modules that potentially doubles the output.

EMI — Electromagnetic interference.

device driver — A program that allows the operating

ERA — Embedded remote access. ERA allows you to

system or some other program to interface correctly with a

perform remote, or "out-of-band," server management on

peripheral. Some device drivers—such as network

your network server using a remote access controller.

drivers—must be loaded from the config.sys file or as

ESD — Electrostatic discharge.

memory-resident programs (usually, from the autoexec.bat

ESM — Embedded server management.

file). Others must load when you start the program for which

they were designed.

expansion bus — Your system contains an expansion bus

that allows the processor to communicate with controllers

DHCP — Dynamic Host Configuration Protocol. A method

for peripherals, such as NICs.

of automatically assigning an IP address to a client system.

diagnostics — A comprehensive set of tests for your

system.

148 Glossary

expansion card — An add-in card, such as a NIC or SCSI

guarding — A type of data redundancy in which a set of

adapter, that plugs into an expansion-card connector on the

physical drives stores data and an additional drive stores

system board. An expansion card adds some specialized

parity data. See also mirroring, striping, and RAID.

function to the system by providing an interface between the

h — Hexadecimal. A base-16 numbering system, often used

expansion bus and a peripheral.

in programming to identify addresses in the system’s RAM

expansion-card connector — A connector on the system

and I/O memory addresses for devices. In text, hexadecimal

board or riser board for plugging in an expansion card.

numbers are often followed by h.

F — Fahrenheit.

headless system — A system or device that functions

without having a keyboard, mouse, or monitor attached.

FAT — File allocation table. The file system structure used

Normally, headless systems are managed over a network

by MS-DOS to organize and keep track of file storage. The

®

®

using an Internet browser.

Microsoft

Windows

operating systems can optionally use

a FAT file system structure.

host adapter — A host adapter implements communication

between the system’s bus and the controller for a peripheral

FBD — Fully buffered DIMM.

device. (Hard-drive controller subsystems include

flash memory — A type of EEPROM chip that can be

integrated host adapter circuitry.) To add a SCSI expansion

reprogrammed from a utility on diskette while still installed

bus to your system, you must install or connect the

in a system; most EEPROM chips can only be rewritten

appropriate host adapter.

with special programming equipment.

hot plug — Describes the feature of the system that enables

format — To prepare a hard drive or diskette for storing

you to swap a component of the system while the system is

files. An unconditional format deletes all data stored on the

running.

disk.

Hz — Hertz.

FSB — Front-side bus. The FSB is the data path and

I/O — Input/output. A keyboard is an input device, and a

physical interface between the processor and the main

monitor is an output device. In general, I/O activity can be

memory (RAM).

differentiated from computational activity.

ft — Feet.

ID

— Identification.

FTP — File transfer protocol.

IDE — Integrated drive electronics. A standard interface

g — Gram(s).

between the system board and storage devices.

G — Gravities.

integrated mirroring — Provides simultaneous physical

Gb — Gigabit(s); 1024 megabits or 1,073,741,824 bits.

mirroring of two drives. Integrated mirroring functionality

is provided by the system’s hardware. See also mirroring.

GB — Gigabyte(s); 1024 megabytes or

1,073,741,824 bytes. However, when referring to hard-drive

internal processor cache — An instruction and data cache

capacity, the term is usually rounded to 1,000,000,000

built into the processor.

bytes.

IP — Internet Protocol.

graphics mode — A video mode that can be defined as x

IPX — Internet package exchange.

horizontal by y vertical pixels by z colors.

IRQ — Interrupt request. A signal that data is about to be

group — As it relates to DMI, a group is a data structure

sent to or received by a peripheral device travels by an IRQ

that defines common information, or attributes, about a

line to the processor. Each peripheral connection must be

manageable component.

assigned an IRQ number. Two devices can share the same

IRQ assignment, but you cannot operate both devices

simultaneously.

Glossary 149

jumper — Small blocks on a circuit board with two or more

local bus — On a system with local-bus expansion

pins emerging from them. Plastic plugs containing a wire fit

capability, certain peripheral devices (such as the video

down over the pins. The wire connects the pins and creates a

adapter circuitry) can be designed to run much faster than

circuit, providing a simple and reversible method of

they would with a traditional expansion bus. See also bus.

changing the circuitry in a board.

LVD — Low voltage differential.

K — Kilo-; 1000.

m — Meter(s).

Kb — Kilobit(s); 1024 bits.

mA — Milliampere(s).

KB — Kilobyte(s); 1024 bytes.

MAC address — Media Access Control address. Your

Kbps — Kilobit(s) per second.

system’s unique hardware number on a network.

KBps — Kilobyte(s) per second.

mAh — Milliampere-hour(s).

key combination — A command requiring you to press

Mb — Megabit(s); 1,048,576 bits.

multiple keys at the same time (for example,

MB — Megabyte(s); 1,048,576 bytes. However, when

<Ctrl><Alt><Del>).

referring to hard-drive capacity, the term is often rounded to

kg — Kilogram(s); 1000 grams.

mean 1,000,000 bytes.

kHz — Kilohertz.

Mbps — Megabits per second.

KMM — Keyboard/monitor/mouse.

MBps — Megabytes per second.

KVM — Keyboard/video/mouse. KVM refers to a switch

MBR — Master boot record.

that allows selection of the system from which the video

memory address — A specific location, usually expressed

is displayed and for which the keyboard and mouse are

as a hexadecimal number, in the system’s RAM.

used.

memory module — A small circuit board containing

LAN — Local area network. A LAN is usually confined to

DRAM chips that connects to the system board.

the same building or a few nearby buildings, with all

memory — An area in your system that stores basic system

equipment linked by wiring dedicated specifically to the

data. A system can contain several different forms of

LAN.

memory, such as integrated memory (ROM and RAM) and

lb — Pound(s).

add-in memory modules (DIMMs).

LCD — Liquid crystal display.

MHz — Megahertz.

LED — Light-emitting diode. An electronic device that

mirroring — A type of data redundancy in which a set of

lights up when a current is passed through it.

physical drives stores data and one or more sets of

LGA — Land grid array. A type of processor socket. Unlike

additional drives stores duplicate copies of the data.

the PGA interface, the LGA interface has no pins on the

Mirroring functionality is provided by software. See also

chip; instead, the chip has pads that contact pins on the

guarding, integrated mirroring, striping, and RAID.

system board.

mm — Millimeter(s).

Linux — A UNIX-like operating system that runs on a

ms — Millisecond(s).

variety of hardware systems. Linux is open source software,

®

MS-DOS

— Microsoft Disk Operating System.

which is freely available; however, the full distribution of

Linux along with technical support and training are

available for a fee from vendors such as Red Hat Software.

150 Glossary

NAS — Network Attached Storage. NAS is one of the

processor — The primary computational chip inside the

concepts used for implementing shared storage on a

system that controls the interpretation and execution of

network. NAS systems have their own operating systems,

arithmetic and logic functions. Software written for one

integrated hardware, and software that are optimized to

processor must usually be revised to run on another

serve specific storage needs.

processor. CPU is a synonym for processor.

NIC — Network interface controller. A device that is

protected mode — An operating mode that allows

installed or integrated in a system to allow connection to a

operating systems to implement:

network.

• A memory address space of 16 MB to 4 GB

NMI — Nonmaskable interrupt. A device sends an NMI to

• Multitasking

signal the processor about hardware errors.

• Virtual memory, a method for increasing addressable

ns — Nanosecond(s).

memory by using the hard drive

NTFS — The NT File System option in the Windows 2000

The Windows 2000 and UNIX 32-bit operating systems run

operating system.

in protected mode. MS-DOS cannot run in protected mode.

NVRAM — Nonvolatile random-access memory. Memory

PS/2 — Personal System/2.

that does not lose its contents when you turn off your

PXE — Preboot eXecution Environment. A way of booting

system. NVRAM is used for maintaining the date, time, and

a system via a LAN (without a hard drive or bootable

system configuration information.

diskette).

parity — Redundant information that is associated with a

RAC

— Remote access controller.

block of data.

RAID — Redundant array of independent disks. A method

partition — You can divide a hard drive into multiple

of providing data redundancy. Some common

physical sections called partitions with the fdisk command.

implementations of RAID include RAID 0, RAID 1,

Each partition can contain multiple logical drives. You must

RAID 5, RAID 10, and RAID 50. See also guarding,

format each logical drive with the format command.

mirroring, and striping.

PCI — Peripheral Component Interconnect. A standard for

RAM — Random-access memory. The system’s primary

local-bus implementation.

temporary storage area for program instructions and data.

PDU — Power distribution unit. A power source with

Any information stored in RAM is lost when you turn off

multiple power outlets that provides electrical power to

your system.

servers and storage systems in a rack.

RAS — Remote Access Service. This service allows users

peripheral — An internal or external device, such as a

running the Windows operating system to remotely access a

diskette drive or keyboard, connected to a system.

network from their system using a modem.

PGA — Pin grid array. A type of processor socket that

readme file — A text file, usually shipped with software or

allows you to remove the processor chip.

hardware, that contains information supplementing or

updating the product’s documentation.

pixel — A single point on a video display. Pixels are

arranged in rows and columns to create an image. A video

read-only file — A read-only file is one that you are

resolution, such as 640 x 480, is expressed as the number of

prohibited from editing or deleting.

pixels across by the number of pixels up and down.

ROM — Read-only memory. Your system contains some

POST — Power-on self-test. Before the operating system

programs essential to its operation in ROM code. A ROM

loads when you turn on your system, the POST tests various

chip retains its contents even after you turn off your system.

system components such as RAM and hard drives.

Examples of code in ROM include the program that initiates

your system’s boot routine and the POST.

Glossary 151

ROMB — RAID on motherboard.

striping — Disk striping writes data across three or more

disks in an array, but only uses a portion of the space on

rpm — Revolutions per minute.

each disk. The amount of space used by a "stripe" is the

RTC — Real-time clock.

same on each disk used. A virtual disk may use several

SAS — Serial-attached SCSI.

stripes on the same set of disks in an array. See also

guarding, mirroring, and RAID.

SATA — Serial Advanced Technology Attachment. A

standard interface between the system board and storage

SVGA — Super video graphics array. VGA and SVGA are

devices.

video standards for video adapters with greater resolution

and color display capabilities than previous standards.

SCSI — Small computer system interface. An I/O bus

interface with faster data transmission rates than standard

system board — As the main circuit board, the system

ports.

board usually contains most of your system’s integral

components, such as the processor, RAM, controllers for

SDRAM — Synchronous dynamic random-access memory.

peripherals, and various ROM chips.

sec — Second(s).

system configuration information — Data stored in

SEL — System event log. Used in the system management

memory that tells a system what hardware is installed and

software to record system events and errors.

how the system should be configured for operation.

serial port — An I/O port used most often to connect a

system diskette — See bootable diskette

.

modem to your system. You can usually identify a serial

system memory — See RAM.

port on your system by its 9-pin connector.

System Setup program — A BIOS-based program that

service tag — A bar code label on the system used to

allows you to configure your system’s hardware and

identify it when you call Dell for technical support.

customize the system’s operation by setting features such as

simple disk volume — The volume of free space on a

password protection. Because the System Setup program is

single dynamic, physical disk.

stored in NVRAM, any settings remain in effect until you

SMART — Self-Monitoring Analysis and Reporting

change them again.

Technology. Allows hard drives to report errors and failures

system.ini file — A start-up file for the Windows operating

to the system BIOS and then display an error message on

system. When you start Windows, it consults the system.ini

the screen.

file to determine a variety of options for the Windows

SMP — Symmetric multiprocessing. Used to describe a

operating environment. Among other things, the system.ini

system that has two or more processors connected via a

file records which video, mouse, and keyboard drivers are

high-bandwidth link and managed by an operating system,

installed for Windows.

where each processor has equal access to I/O devices.

TCP/IP — Transmission Control Protocol/Internet

SNMP — Simple Network Management Protocol. A

Protocol.

standard interface that allows a network manager to

termination — Some devices (such as the last device at

remotely monitor and manage workstations.

each end of a SCSI cable) must be terminated to prevent

spanning — Spanning, or concatenating, disk volumes

reflections and spurious signals in the cable. When such

combines unallocated space from multiple disks into one

devices are connected in a series, you may need to enable or

logical volume, allowing more efficient use of all the space

disable the termination on these devices by changing jumper

and all drive letters on a multiple-disk system.

or switch settings on the devices or by changing settings in

the configuration software for the devices.

152 Glossary

UNIX — Universal Internet Exchange. UNIX, the

video resolution — Video resolution (800 x 600, for

precursor to Linux, is an operating system written in the C

example) is expressed as the number of pixels across by the

programming language.

number of pixels up and down. To display a program at a

specific graphics resolution, you must install the appropriate

uplink port — A port on a network hub or switch used to

video drivers and your monitor must support the resolution.

connect to other hubs or switches without requiring a

crossover cable.

W — Watt(s).

UPS — Uninterruptible power supply. A battery-powered

WH — Watt-hour(s).

unit that automatically supplies power to your system in the

win.ini file — A start-up file for the Windows operating

event of an electrical failure.

system. When you start Windows, it consults the win.ini file

USB — Universal Serial Bus. A USB connector provides a

to determine a variety of options for the Windows operating

single connection point for multiple USB-compliant

environment. The win.ini file also usually includes sections

devices, such as mice and keyboards. USB devices can be

that contain optional settings for Windows application

connected and disconnected while the system is running.

programs that are installed on the hard drive.

utility — A program used to manage system resources—

Windows 2000 — An integrated and complete Microsoft

memory, disk drives, or printers, for example.

Windows operating system that does not require MS-DOS

and that provides advanced operating system performance,

UTP — Unshielded twisted pair. A type of wiring used to

improved ease of use, enhanced workgroup functionality,

connect systems in a business or home to a telephone line.

and simplified file management and browsing.

V — Volt(s).

Windows Powered — A Windows operating system

VA C — Volt(s) alternating current.

designed for use on NAS systems. For NAS systems, the

VDC — Volt(s) direct current.

Windows Powered operating system is dedicated to file

service for network clients.

VGA — Video graphics array. VGA and SVGA are video

standards for video adapters with greater resolution and

Windows Server 2003 — A set of Microsoft software

color display capabilities than previous standards.

technologies that enable software integration through the

use of XML Web services. XML Web services are small

video adapter — The logical circuitry that provides (in

reusable applications written in XML that allow data to be

combination with the monitor) your system’s video

communicated between otherwise unconnected sources.

capabilities. A video adapter may be integrated into the

system board or may be an expansion card that plugs into an

XML — Extensible Markup Language. XML is a way to

expansion slot.

create common information formats and to share both the

format and the data on the World Wide Web, intranets, and

video driver — A program that allows graphics-mode

elsewhere.

application programs and operating systems to display at a

chosen resolution with the desired number of colors. Video

ZIF — Zero insertion force.

drivers may need to match the video adapter installed in the

system.

video memory — Most VGA and SVGA video adapters

include memory chips in addition to your system’s RAM.

The amount of video memory installed primarily influences

the number of colors that a program can display (with the

appropriate video drivers and monitor capabilities).

Glossary 153