Dell™ PowerVault™ 715N Systems User's Guide
The following list defines or identifies technical terms, abbreviations, and acronyms used in Dell user documents.
Abbreviation for ampere(s).
Abbreviation for alternating current.
An expansion card that plugs into an expansion-card connector on the system board. An adapter card adds some specialized function to the system by providing an interface between the expansion bus and a peripheral device. Examples of adapter cards include network cards, sound cards, and SCSI adapters.
An individual code assigned to a system, usually by a system administrator, for security or tracking purposes.
A copy of a program or data file. As a precaution, you should back up your system's hard drive on a regular basis. Before making a change to the configuration of your system, you should back up important startup files from your operating system.
Acronym for basic input/output system. Your system's BIOS contains programs stored on a flash memory chip. The BIOS controls the following:
The smallest unit of information interpreted by your system.
When you start your system, it clears all memory, initializes devices, and loads the operating system. Unless the operating system fails to respond, you can reboot (also called warm boot) your system by pressing <Ctrl><Alt><Delete>; otherwise, you must perform a cold boot by pressing the reset button or by turning the system off, and then back on.
Abbreviation for bits per second.
An information pathway between the components of a system. Your system contains an expansion bus that allows the microprocessor to communicate with controllers for all the various peripheral devices connected to the system. Your system also contains an address bus and a data bus for communications between the microprocessor and RAM.
Eight contiguous bits of information, the basic data unit used by your system.
Abbreviation for Celsius.
A fast storage area that keeps a copy of data or instructions for quicker data retrieval. For example, your system's BIOS may cache ROM code in faster RAM, or a disk-cache utility may reserve RAM in which to store frequently accessed information from your system's disk drives; when a program makes a request to a drive for data that is in the cache, the disk-cache utility can retrieve the data from RAM faster than from the hard drive.
The device names for the first through fourth serial ports on your system are COM1, COM2, COM3, and COM4. The default interrupt for COM1 and COM3 is IRQ4, and the default interrupt for COM2 and COM4 is IRQ3. Therefore, you must be careful when configuring software that runs a serial device so that you do not create an interrupt conflict.
A chip that controls the transfer of data between the microprocessor and memory or between the micro-processor and a peripheral device such as a hard drive or the keyboard.
The part of the system that contains indicators and controls, such as the power switch, hard drive access indicator, and power indicator.
The first 640 KB of RAM. Conventional memory is found in all systems. Unless they are specially designed, MS-DOS® programs are limited to running in conventional memory.
A chip that relieves the system's microprocessor of specific processing tasks. A math coprocessor, for example, handles numeric processing. A graphics coprocessor handles video rendering. The Intel® Pentium® microprocessor, for example, includes a built-in math coprocessor.
Abbreviation for centimeter.
Abbreviation for central processing unit. See microprocessor.
Abbreviation for direct current.
A comprehensive set of diagnostic tests for your Dell system. You can run the diagnostics from either the utility partition on your hard drive or from a set of diskettes that you create from the Resource CD. See your Installation and Troubleshooting Guide for more information about using the system diagnostics.
A program that allows the operating system or some other program to interface correctly with a peripheral device, such as a printer. Some device drivers, such as network drivers, must be loaded from the config.sys file (with a device= statement) or as memory-resident programs (usually, from the autoexec.bat file). Others—such as video drivers—must load when you start the program for which they were designed.
Acronym for dual in-line memory module. A small circuit board containing DRAM chips that connects to the system board.
Acronym for Deutsche Industrie Norm.
Directories help keep related files organized on a disk in a hierarchical, "inverted tree" structure. Each disk has a "root" directory; for example, a C:\> prompt normally indicates that you are at the root directory of hard drive C. Additional directories that branch off of the root directory are called subdirectories. Subdirectories may contain additional directories branching off of them.
Abbreviation for direct memory access. A DMA channel allows certain types of data transfer between RAM and a device to bypass the microprocessor.
Abbreviation for dynamic random-access memory. A system's RAM is usually made up entirely of DRAM chips. Because DRAM chips cannot store an electrical charge indefinitely, your system continually refreshes each DRAM microprocessor in the system.
Your system can recognize a number of specific hard drives. Each is assigned a drive-type number that is stored in SDRAM. The hard drive(s) specified in your system's System Setup program must match the actual drive(s) installed in the system. The System Setup program also allows you to specify physical parameters (logical cylinders, logical heads, cylinder number, and logical sectors per pack) for drives not included in the table of drive types stored in SDRAM.
Abbreviation for error checking and correction.
Acronym for electrically erasable programmable read-only memory.
Abbreviation for electromagnetic compatibility.
Abbreviation for electromagnetic interference.
Your system contains an expansion bus that allows the microprocessor to communicate with controllers for peripheral devices, such as a network card or an internal modem.
A connector on the system board or riser board for plugging in an expansion card.
RAM above 1 MB. Most software that can use it, such as the Windows operating system, requires that extended memory be under the control of an XMM.
Abbreviation for fahrenheit.
To prepare a hard drive or diskette for storing files. An unconditional format deletes all data stored on the disk.
Abbreviation for feet.
Abbreviation for gram(s).
Abbreviation for gigabyte(s). A gigabyte equals 1,024 megabytes or 1,073,741,824 bytes.
A host adapter implements communication between the system's bus and the controller for a peripheral device. (Hard drive controller subsystems include integrated host adapter circuitry.) To add a SCSI expansion bus to your system, you must install or connect the appropriate host adapter.
Abbreviation for hertz.
Abbreviation for input/output. The keyboard is an input device, and a printer is an output device. In general, I/O activity can be differentiated from computational activity.
For example, when a program sends a document to the printer, it is engaging in output activity; when the program sorts a list of terms, it is engaging in computational activity.
Abbreviation for identification.
An instruction and data cache built in to the microprocessor. The Intel Pentium microprocessor includes a 16-KB internal cache, which is set up as an 8-KB read-only instruction cache and an 8-KB read/write data cache.
Abbreviation for interrupt request. A signal that data is about to be sent to or received by a peripheral device travels by an IRQ line to the microprocessor. Each peripheral connection must be assigned an IRQ number. For example, the first serial port in your system (COM1) is assigned to IRQ4 by default. Two devices can share the same IRQ assignment, but you cannot operate both devices simultaneously.
Acronym for Industry-Standard Architecture. A 16-bit expansion bus design. The expansion-card connectors in an ISA system are also compatible with 8-bit ISA expansion cards.
Abbreviation for kilobyte(s), 1,024 bytes.
Abbreviation for kilobit(s), 1,024 bits.
A command requiring you to press multiple keys at the same time. For example, you can reboot your system by pressing the <Ctrl><Alt><Delete> key combination.
Abbreviation for kilogram(s), 1,000 grams.
Abbreviation for kilohertz, 1,000 hertz.
Abbreviation for pound(s).
Abbreviation for light-emitting diode. An electronic device that lights up when a current is passed through it.
On a system with local-bus expansion capability, certain peripheral devices (such as the video adapter circuitry) can be designed to run much faster than they would with a traditional expansion bus. Some local-bus designs allow peripherals to run at the same speed and with the same width data path as the system's microprocessor.
Abbreviation for meter(s).
Abbreviation for megabit.
Abbreviation for megabyte(s). The term megabyte means 1,048,576 bytes; however, when referring to hard drive storage, the term is often rounded to mean 1,000,000 bytes.
Abbreviation for megabytes per second.
Abbreviation for megabits per second.
A system can contain several different forms of memory, such as RAM, ROM, and video memory. Frequently, the word "memory" is used as a synonym for RAM; for example, an unqualified statement such as "a system with 16 MB of memory" refers to a system with 16 MB of RAM.
A small circuit board containing DRAM chips that connects to the system board.
Abbreviation for megahertz.
The primary computational chip inside the system that controls the interpretation and execution of arithmetic and logic functions. Software written for one microprocessor must usually be revised to run on another microprocessor. CPU is a synonym for microprocessor.
Abbreviation for millimeter(s).
A pointing device that controls the movement of the cursor on a screen. Mouse-aware software allows you to activate commands by clicking a mouse button while pointing at objects displayed on the screen.
Abbreviation for Microsoft Disk Operating System.
Abbreviation for network attached storage.
Acronym for network interface controller.
Abbreviation for 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.
An I/O port used most often to connect a parallel printer to your system. You can usually identify a parallel port on your system by its 25-hole connector.
Abbreviation for Peripheral Component Interconnect. A standard for local-bus implementation developed by Intel Corporation.
An internal or external device—such as a printer, a hard drive, or a keyboard—connected to a system.
Acronym for power-on self-test. Before the operating system loads when you turn on your system, the POST tests various system components such as RAM, the hard drives, and the keyboard.
Acronym for redundant arrays of independent disks. This phrase was introduced by David Patterson, Garth Gibson, and Randy Katz at the University of California at Berkeley in 1987. The goal of RAID is to use multiple small, inexpensive disk drives to provide high storage capacity and performance while maintaining or improving the reliability of the disk subsystem.
Patterson, Gibson, and Katz described five different methods, which are known as RAID levels 1 through 5. Each level uses one or more extra drives to provide a means of recovering data lost when a disk fails, so that the effective failure rate of the whole disk subsystem becomes very low.
RAID 0 is commonly called striping. This was not originally defined as a RAID level but has since come into popular use. In this array configuration, data is written sequentially across the available disks and no redundancy is provided. RAID 0 configurations provide very high performance but relatively low reliability. RAID 0 is the best choice when controller cards are duplexed. See striping.
RAID 1 is commonly called mirroring. RAID 1 also uses striping, so RAID 1 may be regarded as the mirroring of RAID 0 configurations. RAID 1 is the best choice in high-availability applications that require high performance or relatively low data capacity. See mirroring, RAID 10, striping.
RAID 4 is commonly called guarding. It uses data striping, like RAID 0, but adds a single, dedicated parity drive. The parity data stored on this drive can be used to recover data lost from a single failed drive. RAID 4 configurations write data slowly because parity data has to be generated and written to the parity drive, and the generation of the parity data frequently requires reading data from multiple physical drives. See guarding and striping.
RAID 5, like RAID 4, is commonly called guarding. RAID 5 is identical to RAID 4, except that the parity data is distributed evenly across all physical drives instead of a parity drive. In configurations using a large number of physical drives in which a large number of simultaneous small write operations are being performed, RAID 5 offers potentially higher performance than RAID 4. RAID 4 and RAID 5 configurations are appropriate in high-availability applications where performance is less critical or where high-data capacity is required. See guarding.
RAID 10 is a mirroring technique in which data is duplicated across two identical RAID 0 arrays or hard drives. All data on a physical drive in one array is duplicated, or mirrored, on a drive in the second array. Mirroring offers complete redundancy of data for greater data security. See mirroring, RAID 1, and striping.
Acronym for random-access memory. The system's primary temporary storage area for program instructions and data. Each location in RAM is identified by a number called a memory address. Any information stored in RAM is lost when you turn off your system.
Abbreviation for remote access services.
A text file included with a software package or hardware product that contains information supplementing or updating the documentation for the software or hardware. Typically, readme files provide installation information, describe new product enhancements or corrections that have not yet been documented, and list known problems or other things you need to be aware of as you use the software or hardware.
Acronym for read-only memory. Your system contains some programs essential to its operation in ROM code. Unlike RAM, a ROM 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.
Abbreviation for revolutions per minute.
Acronym for small computer system interface. An I/O bus interface with faster data transmission rates than standard ports. You can connect up to seven devices (15 for some newer SCSI types) to one SCSI interface.
Abbreviation for SCSI device management system.
Abbreviation for synchronous dynamic random-access memory.
Abbreviation for second(s).
An I/O port used most often to connect a modem to your system. You can usually identify a serial port on your system by its 9-pin connector.
A bar code label on the system that identifies it when you call Dell for customer or technical support.
Acronym for single in-line memory module. A small circuit board containing DRAM chips that connects to the system board.
Abbreviation for symmetric multiprocessing.
Abbreviation for Simple Network Management Protocol. SNMP is an industry-standard interface that allows a network manager to remotely monitor and manage workstations.
In composite drivers with two or more physical drives, the drive array subsystem uses a method of data storage called striping. With this method, data is divided into a series of pieces called blocks and each data block is stored on a different physical drive. When each drive contains a block of data, the process starts over with the first physical drive. When the size of the data block is carefully selected, the chance that the information needed can be read from or written to multiple physical drives at once is increased, greatly increasing the performance of the composite drive. See RAID.
As the main circuit board, the system board usually contains most of your system's integral components, such as the following:
Frequently used synonyms for system board are motherboard and logic board.
Data stored in memory that tells a system what hardware is installed and how the system should be configured for operation.
System memory is a synonym for RAM.
A BIOS-based program that allows you to configure your system's hardware and customize the system's operation by setting such features as password protection and energy management. Some options in the System Setup program require that you reboot the system (or the system may reboot automatically) in order to make a hardware configuration change. Because the System Setup program is stored in NVRAM, any settings remain in effect until you change them again.
A startup file for the Windows operating system. When you start Windows, it consults the system.ini file to determine a variety of options for the Windows operating environment.
Running the Control Panel or Windows Setup program might change options in the system.ini file. On other occasions, you might need to change or add options to the system.ini file manually with a text editor, such as Notepad.
Abbreviation for universal asynchronous receiver-transmitter.
The 384 KB of RAM located between 640 KB and 1 MB. If the system has an Intel386 or higher microprocessor, a utility called a memory manager can create UMBs in the upper-memory area, in which you can load device drivers and memory-resident programs.
Abbreviation for uninterruptible power supply. A battery-powered unit that automatically supplies power to your system in the event of an electrical failure.
A program used to manage system resources—memory, hard drives, or printers, for example.
Abbreviation for volt(s).
Abbreviation for watt(s).