LSI MegaRAID Express 500 - Manual (Page 37)

Chapter 3 RAID Levels 23
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 Express 500 uses the parity drive 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 15