Understanding Drive Arrays; What Is A Drive Array - Compaq 3200 Reference Manual

Appendix E

Understanding Drive Arrays

This chapter explains drive array concepts, data protection methods (including
fault-tolerance options), and data reliability features of the Smart Array 3200
Controller. The following general information will help you understand terms
and concepts required for configuration.

What is a Drive Array?

A drive array is a collection of hard disk drives or physical drives that are
grouped together to create an array of physical drives. An array is made up of
one or more subsets called logical drives (sometimes called logical volumes),
that are spread across all physical drives in the array. Operating systems view
logical drives as a single, contiguous storage space, although it is made up of
parts of several physical drives.
The generic drive array illustrated in Figure E-1 consists of two logical drives
spread across three physical drives. Figures E-2 through E-4 illustrate other
drive array configurations.
Daz-9-12.EPS
Figure E-1. Drive array with two logical drives
Writer: Rickard Project: Compaq Smart Array 3200 Controller Reference Guide Comments: 340862-002
File Name: L-APPE.DOC Last Saved On: 12/7/98 9:30 AM
COMPAQ CONFIDENTIAL - NEED TO KNOW REQUIRED
Physical Physical
Drive 1 Drive 2
Drive Array
Physical
Drive 3
Logical
Drive 1
Logical
Drive 2
Compaq Smart Array 3200 Controller Reference Guide
E-1