
RAID 5
| RAID 5 includes disk striping at the byte level and parity. In RAID 5, the parity information is |
| written to several drives. RAID 5 is best suited for networks that perform a lot of small I/O |
| transactions simultaneously. |
| RAID 5 addresses the bottleneck issue for random I/O operations. Since each drive contains both |
| data and parity numerous writes can take place concurrently. In addition, robust caching algorithms |
| and hardware based |
| environments. |
Uses | RAID 5 provides high data throughput, especially for large |
| files. Use RAID 5 for transaction processing applications |
| because each drive can read and write independently. If a |
| drive fails, MegaRAID uses distributed parity to recreate all |
| missing information. Use also for office automation and |
| online customer service that requires fault tolerance. Use for |
| any application that has high read request rates but low |
| write request rates. |
Strong Points | Provides data redundancy and good performance in most |
| environments |
Weak Points | Disk drive performance will be reduced if a drive is being |
| rebuilt. Environments with few processes do not perform as |
| well because the RAID overhead is not offset by the |
| performance gains in handling simultaneous processes. |
Drives | Three to 32 |
Chapter 3 RAID Levels | 21 |