LSI MegaRAID Enterprise 1600 - Manual (Page 35)

Chapter 3 RAID Levels 21
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 exclusive-or assist make RAID 5 performance exceptional in many different
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