Acer SmartRAID V Bedienungsanleitung PDF herunterladen (Seite 245)

G-5

Glossary

HSSDC

High Speed Serial Data Connector. The industry

standard modular connector used on Fibre

Channel controllers.

I

2

O

Intelligent I/O Architecture. A proprietary

specification that provides a standardized

software interface between peripheral devices

with built-in intelligence and a host operating

system.

ID

A numeric value used by SCSI devices to

address one another. (IDs can be from 0 to 7 or

0 to 15 for Wide SCSI.) Fibre Channel devices

can have ID numbers from 0 to 126.

Information View

The view in SMOR that provides a display of

device specific information when that device is

highlighted in the Tree View. The information

on this view may be further grouped into Tab

Pages.

Initiator

A SCSI device, such as a SmartRAID V

controller, that sends commands to SCSI Target

devices such as disk drives.

IRQ

Interrupt ReQuest. A hardware interrupt on a

computer. Systems that use the IBM/Intel

architecture have 16 IRQ lines used to signal

the CPU when a peripheral event has started or

terminated. Except for PCI devices, two devices

cannot use the same line. The PCI bus allows

IRQs to be shared between devices.

Latency

The time required by a device to access stored

data, excluding the data transfer time. Reducing

disk latency results in more I/O operations per

second being performed on a disk drive.

LBA

Logical Block Address. A method of addressing

storage blocks on a disk drive in a linear

fashion, rather than by Cylinder, Track and

Sector. This technique also overcomes storage

addressing limitations on some systems.

LED

Light Emitting Diode. An electronic device that

gives off light when power is applied.

LRU

Least Recently Used. A cache management

algorithm employed by SmartRAID V to

determine the next cache page to delete and

reuse when all pages have been filled with data.

By deleting the page in cache that has gone the

longest without an access, the algorithm

ensures that the most frequently accessed data

is resident in the cache.

LSU

Logical Storage Unit. A device on which the

computer can store and retrieve information.

This can be an individual disk drive or an array

group.

LUN

Logical Unit Number. Each SCSI device can

contain up to eight sub-devices or logical units.

The logical units are assigned from 0 to 7.

Typically, SCSI devices such as a disk or tape

drive contain only one subunit (LUN 0).

LVD SCSI

Low Voltage Differential SCSI. A SCSI-3

transmission protocol that provides long cable

lengths without the need for external high

voltage bus transceivers. The maximum

synchronous transfer rate is 40MHz. Also known

as Ultra2 SCSI.

MIA

Media Interface Adapter. A device that converts

electrical signals to optical fiber signals for

Fibre Channel connections.

Mirroring

A popular term for RAID 1. It refers to the

method of creating disk-fault tolerance by

storing duplicate information on pairs of drives.

Miss

A data access in which the requested data is not

found in cache.

1 2 ... 240 241 242 243 244 245 246 247 248 249 250 ... 255 256

Kommentare zu diesen Handbüchern

Keine Kommentare