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2 RAID Overview
This chapter summarizes concepts and terminology used to describe RAID
systems. It describes the different RAID levels available with the HP NetRAID-
1M and 2M adapters. For definitions of terms not introduced here, see the
Glossary later in this guide.
RAID Overview
HP NetRAID-1M and 2M adapters let you link multiple hard disk drives together
and write data across them as if they were one large drive. With the
HP NetRAID-1M and 2M adapters, you can configure your linked drives into a
RAID (Redundant Array of Independent Disks) subsystem.
Physical Drives
The term "physical drive" refers to a single hard disk module.
Figure 2-1. Physical Drive
Arrays
HP NetRAID-1M and 2M adapters can combine multiple physical drives into one
array (see Appendix A, "Adapter Specifications"). It is recommended that all
drives in an array have the same capacity. If you use drives with different
capacities in an array, all the drives in the array are treated as though they have
the capacity of the smallest drive.
Figure 2-2. Array of Physical Drives
