Table 5.4 | Capacity for RAID Levels (Cont.) | |||
|
|
|
|
|
RAID |
|
| Drives |
|
Level | Description | Required | Capacity | |
|
|
|
| |
10 | Mirroring and | 4 – 18 | (Number of disks) X (capacity of | |
| Striping | (Must be a | smallest disk) / (2) | |
|
|
| multiple of 2.) |
|
|
|
|
| |
50 | RAID 5 and | 6 – 30 (Must | (Number of disks) X (capacity of | |
| Striping | be a multiple | smallest disk) – (capacity of 1 disk X | |
|
|
| of arrays.) | number of Arrays) |
|
|
|
|
|
You can maximize the availability of data on the physical disk drive in the logical array by maximizing the level of fault tolerance. Table 5.5 describes the levels of fault tolerance for the RAID levels.
Table 5.5 | Fault Tolerance for RAID Levels | ||
|
|
| |
RAID Level |
| Fault Tolerance Protection | |
|
|
| |
0 |
| No fault tolerance. | |
|
|
|
|
1 |
| 100% | protection through data mirroring. |
|
|
| |
5 |
| 100% protection through striping and parity. The data is striped | |
|
| and parity data is written across a number of physical disk | |
|
| drives. |
|
|
|
|
|
10 |
| 100% | protection through data mirroring. |
|
|
|
|
50 |
| 100% | protection through data striping and parity. All data is |
|
| striped and parity data is written across all drives in two or | |
|
| more arrays. | |
|
|
|
|
You can configure an array for optimal performance. But optimal drive configuration for one type of application will probably not be optimal for any other application. A basic guideline of the performance characteristics for RAID drive arrays at each RAID level is shown in Table 5.6.
Configuring Physical Drives, Arrays, and Logical Drives | |
| Copyright © 2002 by LSI Logic Corporation. All rights reserved. |