Compaq External RAID Controller & Subsystem Infortrend, Руководство по эксплуатации

Страница: 40 / 347

RAID Planning 2-1
RAID Planning
This chapter summarizes the procedures and provides some useful
tools for first-time configuration:
2.1 Considerations: things you should know before setting
up
2.2 Configuring the
Array:
the most common configuration
procedure
2.3 Operation Theory: the theory behind data bus and system
drive mapping
2.4 Functional Table of
Contents
a useful tool that helps you to quickly
locate a firmware function
2.1 Considerations
After you understand the basic ideas behind RAID levels, you may
still be wondering about how to begin. Here are the answers to
some questions that may help you through the decision making.
1. How many physical drives do you have?
When initially creating the drive groups, you should know how
many drives you have in your RAID system or in the JBOD
attached to the RAID controlling unit.
2. How many drives on each drive channel?
The optimal system planning is always a compromise between
pros and cons. As a general rule, the number of drives you
should connect on each channel equals the data bus bandwidth
divided by the maximum transfer rate you can get from each of
your hard drives. Knowing the mechanical performance of
your hard drives can help to determine how many drives
should be connected over a drive channel.
Always use fast and large drives of the same capacity for your
disk array. A logical drive composed of an adequate number of
Chapter Chapter Chapter Chapter
2222