Dell PowerEdge 860: 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

direct configuration and power management.

a 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

in the U.S.

you 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

basis. Before making a change to the configuration of your

system also contains an address bus and a data bus for

system, back up important start-up files from your

communications between the processor and RAM.

operating 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.

CD — Compact disc. CD drives use optical technology to

read data from CDs.

Glossary 129

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

disk has a “root” directory. Additional directories that

include operating systems, computer systems, expansion

branch off the root directory are called subdirectories.

cards, and peripherals that are compatible with DMI.

Subdirectories may contain additional directories

Each component is made up of groups and attributes that

branching off them.

are defined as 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

system.

to bypass the processor.

control panel — The part of the system that contains

DMI — Desktop Management Interface. DMI enables

indicators and controls, such as the power button and

the management of your system’s software and hardware

power indicator.

by collecting information about the system’s components,

controller — A chip that controls the transfer of data

such as the operating system, memory, peripherals,

between the processor and memory or between the

expansion 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

ESM — Embedded server management.

autoexec.bat 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

for peripherals, such as NICs.

method of automatically assigning an IP address to a

client system.

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

adapter, that plugs into an expansion-card connector on

diagnostics — A comprehensive set of tests for your

the system board. An expansion card adds some

system.

specialized function to the system by providing an

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

interface between the expansion bus and a peripheral.

module.

130 Glossary

expansion-card connector — A connector on the system

headless system — A system or device that functions

board or riser board for plugging in an expansion card.

without having a keyboard, mouse, or monitor attached.

Normally, headless systems are managed over a network

F — Fahrenheit.

using an Internet browser.

FAT — File allocation table. The file system structure

host adapter — A host adapter implements

used by MS-DOS to organize and keep track of file

®

®

communication between the system’s bus and the

storage. The Microsoft

Windows

operating systems can

controller for a peripheral device. (Hard-drive controller

optionally use a FAT file system structure.

subsystems include integrated host adapter circuitry.) To

FBD — Fully buffered DIMM.

add a SCSI expansion bus to your system, you must install

flash memory — A type of EEPROM chip that can be

or connect the appropriate host adapter.

reprogrammed from a utility on diskette while still

hot plug — Describes the feature of the system that

installed in a system; most EEPROM chips can only be

enables you to swap a component of the system while the

rewritten with special programming equipment.

system is running.

format — To prepare a hard drive or diskette for storing

Hz — Hertz.

files. An unconditional format deletes all data stored on

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

the disk.

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

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

differentiated from computational activity.

physical interface between the processor and the main

ID — Identification.

memory (RAM).

IDE — Integrated drive electronics. A standard interface

ft — Feet.

between the system board and storage devices.

FTP — File transfer protocol.

integrated mirroring — Provides simultaneous physical

g — Gram(s).

mirroring of two drives. Integrated mirroring functionality

G — Gravities.

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

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

internal processor cache — An instruction and data cache

built into the processor.

GB — Gigabyte(s); 1024 megabytes or

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

IP — Internet Protocol.

drive capacity, the term is usually rounded to

IPX — Internet package exchange.

1,000,000,000 bytes.

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

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

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

horizontal by y vertical pixels by z colors.

line to the processor. Each peripheral connection must be

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

assigned an IRQ number. Two devices can share the same

that defines common information, or attributes, about a

IRQ assignment, but you cannot operate both devices

manageable component.

simultaneously.

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

jumper — Small blocks on a circuit board with two or

physical drives stores data and an additional drive stores

more pins emerging from them. Plastic plugs containing a

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

wire fit down over the pins. The wire connects the pins

and creates a circuit, providing a simple and reversible

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

method of changing the circuitry in a board.

used in programming to identify addresses in the system’s

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

K — Kilo-; 1000.

hexadecimal numbers are often followed by h.

Kb — Kilobit(s); 1024 bits.

Glossary 131

KB — Kilobyte(s); 1024 bytes.

MAC address — Media Access Control address. Your

system’s unique hardware number on a network.

Kbps — Kilobit(s) per second.

mAh — Milliampere-hour(s).

KBps — Kilobyte(s) per second.

Mb — Megabit(s); 1,048,576 bits.

key combination — A command requiring you to press

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 mean 1,000,000 bytes.

kg — Kilogram(s); 1000 grams.

Mbps — Megabits per second.

kHz — Kilohertz.

MBps — Megabytes per second.

KMM — Keyboard/monitor/mouse.

MBR — Master boot record.

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

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)

lb — Pound(s).

and 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

additional drives stores duplicate copies of the data.

LGA — Land grid array. A type of microprocessor socket.

Mirroring functionality is provided by software. See also

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

guarding, integrated mirroring, striping, and RAID

.

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

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

®

MS-DOS

— Microsoft Disk Operating System.

software, which is freely available; however, the full

NAS — Network Attached Storage. NAS is one of the

distribution of Linux along with technical support and

concepts used for implementing shared storage on a

training are available for a fee from vendors such as

network. NAS systems have their own operating systems,

Red Hat Software.

integrated hardware, and software that are optimized to

local bus — On a system with local-bus expansion

serve specific storage needs.

capability, certain peripheral devices (such as the video

NIC — Network interface controller. A device that is

adapter circuitry) can be designed to run much faster than

installed or integrated in a system to allow connection to a

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

network.

LVD — Low voltage differential.

NMI — Nonmaskable interrupt. A device sends an NMI

m — Meter(s).

to signal the processor about hardware errors.

mA — Milliampere(s).

ns — Nanosecond(s).

132 Glossary

NTFS — The NT File System option in the

protected mode — An operating mode that allows

Windows 2000 operating system.

operating systems to implement:

NVRAM — Nonvolatile random-access memory. Memory

• A memory address space of 16 MB to 4 GB

that does not lose its contents when you turn off your

• Multitasking

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

• Virtual memory, a method for increasing addressable

and system configuration information.

memory by using the hard drive

parity — Redundant information that is associated with a

The Windows 2000 and UNIX 32-bit operating systems

block of data.

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

partition — You can divide a hard drive into multiple

mode.

physical sections called partitions with the fdisk

PS/2 — Personal System/2.

command. Each partition can contain multiple logical

PXE — Preboot eXecution Environment. A way of

drives. You must format each logical drive with the format

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

command.

bootable diskette).

PCI — Peripheral Component Interconnect. A standard

RAC — Remote access controller.

for local-bus implementation.

RAID — Redundant array of independent disks. A

PDU — Power distribution unit. A power source with

method of providing data redundancy. Some common

multiple power outlets that provides electrical power to

implementations of RAID include RAID 0, RAID 1,

servers and storage systems in a rack.

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

peripheral — An internal or external device, such as a

mirroring, and striping.

diskette drive or keyboard, connected to a system.

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

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

temporary storage area for program instructions and data.

allows you to remove the processor chip.

Any information stored in RAM is lost when you turn off

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

your system.

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

RAS — Remote Access Service. This service allows users

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

running the Windows operating system to remotely access

of pixels across by the number of pixels up and down.

a network from their system using a modem.

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

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

loads when you turn on your system, the POST tests

hardware, that contains information supplementing or

various system components such as RAM and hard drives.

updating the product’s documentation.

processor — The primary computational chip inside the

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

system that controls the interpretation and execution of

prohibited from editing or deleting.

arithmetic and logic functions. Software written for one

ROM — Read-only memory. Your system contains some

processor must usually be revised to run on another

programs essential to its operation in ROM code. A ROM

processor. CPU is a synonym for processor.

chip retains its contents even after you turn off your

system. Examples of code in ROM include the program

that initiates your system’s boot routine and the POST.

ROMB — RAID on motherboard.

rpm — Revolutions per minute.

RTC — Real-time clock.

Glossary 133

SAS — Serial-attached SCSI.

striping — Disk striping writes data across three or more

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

SATA — Serial Advanced Technology Attachment. A

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

standard interface between the system board and storage

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

devices.

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

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

guarding, mirroring, and RAID.

interface with faster data transmission rates than standard

SVGA — Super video graphics array. VGA and SVGA are

ports.

video standards for video adapters with greater resolution

SDRAM — Synchronous dynamic random-access

and color display capabilities than previous standards.

memory.

system board — As the main circuit board, the system

sec — Second(s).

board usually contains most of your system’s integral

SEL — System event log. Used in the system

components, such as the processor, RAM, controllers for

management software to record system events and errors.

peripherals, and various ROM chips.

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

system configuration information — Data stored in

modem to your system. You can usually identify a serial

memory that tells a system what hardware is installed and

port on your system by its 9-pin connector.

how the system should be configured for operation.

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

system diskette — See bootable diskette.

identify it when you call Dell for technical support.

system memory — See RAM.

simple disk volume — The volume of free space on a

System Setup program — A BIOS-based program that

single dynamic, physical disk.

allows you to configure your system’s hardware and

SMART — Self-Monitoring Analysis and Reporting

customize the system’s operation by setting features such

Technology. Allows hard drives to report errors and failures

as password protection. Because the System Setup

to the system BIOS and then display an error message on

program is stored in NVRAM, any settings remain in

the screen.

effect until you change them again.

SMP — Symmetric multiprocessing. Used to describe a

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

system that has two or more processors connected via a

operating system. When you start Windows, it consults

high-bandwidth link and managed by an operating

the system.ini file to determine a variety of options for the

system, where each processor has equal access to I/O

Windows operating environment. Among other things,

devices.

the system.ini file records which video, mouse, and

keyboard drivers are installed for Windows.

SNMP — Simple Network Management Protocol. A

standard interface that allows a network manager to

TCP/IP — Transmission Control Protocol/Internet

remotely monitor and manage workstations.

Protocol.

spanning — Spanning, or concatenating, disk volumes

termination — Some devices (such as the last device at

combines unallocated space from multiple disks into one

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

logical volume, allowing more efficient use of all the space

reflections and spurious signals in the cable. When such

and all drive letters on a multiple-disk system.

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

or disable the termination on these devices by changing

jumper or switch settings on the devices or by changing

settings in the configuration software for the devices.

134 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

example) is expressed as the number of pixels across by

C programming language.

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

at a specific graphics resolution, you must install the

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

appropriate video drivers and your monitor must support

connect to other hubs or switches without requiring a

the resolution.

crossover cable.

W — Watt(s).

UPS — Uninterruptible power supply. A battery-powered

unit that automatically supplies power to your system in

WH — Watt-hour(s).

the event of an electrical failure.

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

USB — Universal Serial Bus. A USB connector provides a

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

single connection point for multiple USB-compliant

file to determine a variety of options for the Windows

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

operating environment. The win.ini file also usually

connected and disconnected while the system is running.

includes sections that contain optional settings for

Windows application programs that are installed on the

utility — A program used to manage system resources—

hard drive.

memory, disk drives, or printers, for example.

Windows 2000 — An integrated and complete Microsoft

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

Windows operating system that does not require

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

MS-DOS and that provides advanced operating system

V — Volt(s).

performance, improved ease of use, enhanced workgroup

VAC — Volt(s) alternating current.

functionality, and simplified file management and

browsing.

VDC — Volt(s) direct current.

Windows Powered — A Windows operating system

VGA — Video graphics array. VGA and SVGA are video

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

standards for video adapters with greater resolution and

Windows Powered operating system is dedicated to file

color display capabilities than previous standards.

service for network clients.

video adapter — The logical circuitry that provides (in

®

Windows Server

2003 — A set of Microsoft software

combination with the monitor) your system’s video

technologies that enable software integration through the

capabilities. A video adapter may be integrated into the

use of XML Web services. XML Web services are small

system board or may be an expansion card that plugs into

reusable applications written in XML that allow data to be

an expansion slot.

communicated between otherwise unconnected sources.

video driver — A program that allows graphics-mode

XML — Extensible Markup Language. XML is a way to

application programs and operating systems to display at a

create common information formats and to share both the

chosen resolution with the desired number of colors.

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

Video drivers may need to match the video adapter

and elsewhere.

installed in the system.

ZIF — Zero insertion force.

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 135

136 Glossary