IBM 86624RY Maintenance Manual - Page 78

Data Stripe 1 Mirror Stripe 1 Data Stripe 2 Mirror Stripe 2 . . Block 1 Block 3 Block 4 Block 6 . . Block 2 Block 1 Block 5 Block 4 . . Block 3 Block 2 Block 6 Block 5 RAID level-5: RAID level-5 requires a minimum of three hard disk drives. This RAID level stripes data and parity across all drives in the array. When an array is assigned RAID level-5, the capacity of the logical drive is reduced by one drive (for data-parity storage). RAID level-5 is generally the most desirable choice, because it offers both data protection and increased throughput. RAID level-5 gives higher capacity than RAID level-1, but RAID level-1 offers better performance. The following illustration shows data arranged in an array with three hard disk drives. The logical drive is assigned RAID level-5. Notice that the storage of the data parity also is striped, and it shifts from drive to drive. Stripe 1 Stripe 2 Stripe 3 Stripe 4 . . Block 1 Block 3 Parity 5+6 Block 7 . . Block 2 Parity 3+4 Block 5 Block 8 . . Parity 1+2 Block 4 Block 6 Parity 7+8 ServeRAID Configuration Program The graphical interface in the ServeRAID Configuration Program makes it easy to create, delete, change, or view the ServeRAID configuration. Before beginning, review the following illustration to become familiar with the layout of the configuration program screens. 70 Netfinity Server HMM