User's Manual

HP Smart Array 641/642 Controller User Guide D-1
HP CONFIDENTIAL
Writer: John Turner File Name: l-appd drive arrays & fault tolerance
Codename: darkmatter -antimatter Part Number: 309311-001 Last Saved On: 11/6/02 4:34 PM
D
Drive Arrays and Fault Tolerance
What Is a Drive Array?
The capacity and performance of a single physical (hard) drive is adequate for home
users. However, business users demand higher storage capacities, higher data transfer
rates, and greater protection against data loss when drives fail.
Connecting extra physical drives to a system increases the total storage capacity
(refer to Figure D-1), but has no effect on the efficiency of read/write (R/W)
operations. Data can still be transferred to only one physical drive at a time.
R/W
P1 P2 P3
Figure D-1: Physical drives added to system