System reliability is a vital component in Storage Area Network (SAN) design that keeps your production environment operating and avoids data loss and downtime. But since SANs are built using both mechanical and electronic parts, component failures due to usage, environmental factors, or manufacturing defects are not uncommon. Even in completely redundant systems, controllers can fail, fans can stop operating, power supplies can burn out, and disk drives can degrade or fail.

To eliminate downtime, IT managers should focus on total system design and how components work together to deliver reliability. A common mistake is to evaluate individual component reliability alone -- you can "miss the forest for the trees" and significantly increase expenses with no improvement in overall system reliability.