Summary

Device technology continues to evolve and is being heavily pushed by the requirements of storage networks. In general, bare devices are not addressed individually in a storage network but are part of larger subsystems that provide centralized management for a larger number of resources.

That said, understanding the capabilities and shortcomings of these devices is important to maintaining a well-run SAN environmentespecially where high-performance I/O operations are required. The rotational speed of a drive, its average seek time performance, the relative location of the tracks being used, the number of applications sharing space on the drive, and the amount of buffer memory are all contributing factors that need to be considered for I/O performance tuning in a SAN.

Tape drives have made tremendous strides in the last five years. Capacities and transfer rates have increased by a wide margin, pushed by the enormous amount of data that is being stored. While there are some who believe tape is a dead and dying technology, it is not likely to go away anytime soon because its portability works so well for disaster recovery situations and the ability to restore historical versions of data.