Avago Technologies MegaRAID SATA 150-4 (523) - Manual (Page 68)

3-20 BIOS Configuration Utility and MegaRAID Manager
Version 2.0 Copyright © 2003–2006 by LSI Logic Corporation. All rights reserved.
The number of physical drives in a specific array determines the RAID
levels that you can implement with the array. RAID 0 requires one or
more physical drives. RAID 1 requires exactly two physical drives.
RAID 5 requires at least three physical drives.
Note: The firmware does not support creation of logical drives
greater than 2 Tbytes.
3.4.7.1 Logical Drive Parameters
The following paragraphs describe the parameters that you can set for
the logical drives, which include the RAID level, stripe size, read policy,
write policy, cache policy, and spanning mode.
After you create an array or arrays, you can select the parameters for the
logical drive.
Table 3.10 contains descriptions of the parameters.