The purpose of this document is to provide the reader general guidelines to use when determining the best SMART Array Controller configuration for their particular database server needs. Although absolute performance cannot be precisely predicted, you will have the information needed to make informed configuration choices given your performance, fault-tolerance, and cost constraints.
Drive subsystem performance is one of the most important aspects of tuning a database server for optimal performance. Compaq has designed disk controllers utilizing RAID technology to provide businesses with the best balance of performance, reliability, and availability. RAID technology provides a system with more consistent performance, higher levels of fault-tolerance, and easier fault-recovery than traditional non-RAID systems.
Even though a myriad of artificial benchmarks can be and have been contrived showing non-RAID systems outperforming RAID systems, we have not seen a case of this being true in a production environment. I/O performance is basically limited by the physics of the mechanical nature of disk drives, not I/O buses. Therefore, the configuration and tuning of a system should be focused on getting the most out of each drive and having an appropriate number of drives on a system. When properly configured the I/O subsystem should not be the limiting factor in overall system performance.
The reader should be generally familiar with RAID technology, Compaq drive subsystem terminology, and the use of Compaq System Configuration utilities. Compaq has other publications covering these and related topics listed below:
Compaq SMART Controller User's Guide (142136-001)
Drive Array Advanced Diagnostics User's Guide (137331-001)
SMART Controller Addendum 137536-001 to Manual 137331-001