You can designate drives as hot spares using the MegaRAID BIOS Configuration Utility, the MegaRAID Manager, or Power Console Plus.
5.3Creating Logical Drives
Logical drives are arrays or spanned arrays that are presented to the operating system. You must create one or more logical drives.
The logical drive capacity can include all or any portion of an array. The logical drive capacity can also be larger than an array by using spanning. The MegaRAID SCSI
5.3.1Configuration Strategies
The most important factors in RAID array configuration are: drive capacity, drive availability (fault tolerance), and drive performance. You cannot configure a logical drive that optimizes all three factors, but it is easy to choose a logical drive configuration that maximizes one factor at the expense of the other two factors, although needs are seldom that simple.
5.3.1.1Maximize Capacity
RAID 0 achieves maximum drive capacity, but does not provide data redundancy. Maximum drive capacity for each RAID level is shown below.
Table 5.4 | Capacity for RAID Levels | ||||
|
|
|
|
| |
RAID |
|
| Drives |
| |
Level | Description | Required | Capacity | ||
|
|
|
|
| |
0 | Striping | 1 | – 30 | (Number of disks) X capacity of | |
| without parity |
|
| smallest disk | |
|
|
|
|
| |
1 | Mirroring | 2 |
| (Capacity of smallest disk) X (1) | |
|
|
|
|
| |
5 | Striping with | 3 | – 30 | (Number of disks) X (capacity of | |
| floating parity |
|
| smallest disk) - (capacity of 1 disk) | |
| drive |
|
|
| |
|
|
|
|
|
|
Creating Logical Drives |
Copyright © 2002 by LSI Logic Corporation. All rights reserved.