Channel

Any path used for the transfer of data and control of information between storage devices and a storage controller or I/O adapter. Also refers to one SCSI bus on a disk array controller. Each disk array controller provides at least one channel.

Conservative Cache

An operating mode in which system drives configured with the write-back caching policy are treated as though they were configured for write-through operation and the cache is flushed.

Consistency Check

A process that verifies the integrity of redundant data. A consistency check on a RAID 1 or RAID 0+1 configuration (mirroring) checks if the data on drives and their mirrored pair are exactly the same. For RAID Level 3 or RAID Level 5, a consistency check calculates the parity from the data written on the disk and compares it to the written parity. A consistency check

from Mylex utilities such as Global Array ManagerTM (GAM) or RAID

EzAssistTM give the user the ability to have a discrepancy reported and corrected. See also Parity Check.

Data Transfer Rate

The amount of data per unit of time moved through a channel or I/O Bus in the course of execution of an I/O load, usually expressed in MBps.

DB-9

A type of connector used for serial interfaces.

Device Driver

A software program that controls a particular type of device attached to a computer, such as a RAID subsystem, printer, display, CD-ROM, disk drive, etc.

DIMM

Dual In-line Memory Module, a circuit board that has memory chips. Instead of installing two SIMMs for the 64-bit memory path on a Pentium processor, one DIMM can be installed. See also SIMM.

G-4

AcceleRAID 170 Installation Guide