IBM 86655RY Hardware Maintenance Manual - Page 207

Then, create a logical drive within that array. The data is striped across the drives, creating blocks. Notice that the stripe labeled 5 is the data stripe and the stripe labeled 55 is the copy of the preceding data stripe. Also notice that each block on the mirror stripe is shifted one drive. *1 2 3 ** 3 1 2 *4 5 6 ** 6 4 5 With RAID level-1E, if one of the physical drives fails, the ServeRAID controller switches read and write requests to the remaining functional drives in the RAID level1E array. Understanding RAID level-5: RAID level-5 requires a minimum of three physical drives. This RAID level stripes data and parity across all drives in the array. When you assign RAID level-5 to an array, the capacity of the array is reduced by the capacity of one drive (for data-parity storage). RAID level-5 offers both data protection and increased throughput. RAID level-5 gives you higher capacity than RAID level-1, but RAID level-1 offers better performance. RAID level-5 requires a minimum of 3 drives and supports a maximum of 16 drives. The following illustration is an example of a RAID level-5 logical drive. Start with four physical drives. Installing and configuring ServeRAID controllers 197