Acer AcceleRAID 170 User Manual

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G-4
AcceleRAID 170 Installation Guide
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 Manager
TM
 (GAM) or RAID 
EzAssist
TM
 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.