LSI MegaRAID SCSI 320-2 RAID Controller Series 518 - Manual (Page 70)

5-14 Configuring Physical Drives, Arrays, and Logical Drives
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
must be available 24 hours per day? Will the information stored in this
disk array contain large audio or video files that must be available on
demand? Will this disk array contain data from an imaging system? You
must identify the purpose of the data to be stored in the disk subsystem
before you can confidently choose a RAID level and a RAID
configuration.
5.5 Planning the Array Configuration
Fill out Table 5.8 to help plan this array.
5.5.1 Using the Array Configuration Planner
Table 5.9 lists the possible RAID levels, fault tolerance, and effective
capacity for all possible drive configurations for an array consisting of one
to eight drives. This table does not take into account any hot spare
(standby) drives. You should always have a hot spare drive in case of
drive failure. RAID 1 requires two drives, RAID 10 at least four, and RAID
50 at least six.
Table 5.8 Factors for Planning the Array Configuration
Question Answer
Number of MegaRAID SCSI channels
Number of physical disk drives in the array
Purpose of this array. Rank the following factors:
Maximize drive capacity
Maximize the safety of the data (fault tolerance)
Maximize hard drive performance and throughput
Number of hot spares
Amount of cache memory installed on MegaRAID SCSI 320-1
Are all of the disk drives and the server protected by an
uninterruptible power supply?