Dell MD3000 owner manual 107

NMI — Nonmaskable interrupt. A device sends an NMI to signal the processor about hardware 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 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.

partition — You can divide a physical disk into multiple physical sections called partitions with the fdisk command. Each partition can contain multiple logical disks. You must format each logical disk with the format command.

PCI — Peripheral Component Interconnect. A standard for local-bus implementation.

PDU — Power distribution unit. A power source with multiple power outlets that provides 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 the processor chip.

physical disk — A hard drive installed in the RAID enclosure.

pixel — A single point on a video display. Pixels are arranged in rows and columns to create an image. A video resolution, such as 640 x 480, is expressed as the number of pixels across by the number of pixels up and down.

POST — Power-on self-test. Before the operating system loads when you turn on your system, the POST tests various system components such as RAM and physical disks.

processor — The primary computational chip inside the system that controls the interpretation and execution of arithmetic and logic functions. Software written for one processor must usually be revised to run on another processor. CPU is a synonym for processor.

protected mode — An operating mode that allows operating systems to implement:

•A memory address space of 16 MB to 4 GB

•Multitasking

•Virtual memory, a method for increasing addressable memory by using the physical disk

The Windows 2000 and UNIX® 32-bit operating systems run in protected mode. MS-DOS cannot run in protected mode.

PS/2 — Personal System/2.

PXE — Preboot eXecution Environment. A way of booting a system via a LAN (without a physical disk or bootable diskette).

RAC — Remote access controller.

RAID — Redundant array of independent disks. A method of providing data redundancy. Some common implementations of RAID include RAID 0, RAID 1, RAID 5, RAID 10, and RAID 50. See also guarding, mirroring, and striping.

RAID enclosure — A storage enclosure supporting RAID via a modular controller unit.

RAID array — Collection of storage disks managed under a RAID solution. The RAID array includes any disks attached to the RAID controller, including those contained in a supported expansion enclosure.

RAM — Random-access memory. The system’s primary temporary storage area for program instructions and data. Any information stored in RAM is lost when you turn off your system.

RAS — Remote Access Service. This service allows users running the Windows operating system to remotely access a network from their system using a modem.

readme file — A text file, usually shipped with software or hardware, that contains information supplementing or updating the product’s documentation.

read-only file — A read-only file is one that you are prohibited from editing or deleting.

Glossary

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