HP Surestore E Tape Library Model 6/60 HP SureStore E Tape Library Models 2/20 - Page 210

NOTE Introduction to Fibre Channel Fibre Channel Technology Zoning Zoning is a management method used to control which ports on a hub, or switch, can communicate with each other. Zoned operations are controlled by system administrators and host computer applications. The HP SureStore E Tape Library functions the same on zoned and non-zoned systems. With a hub, zoning divides a larger loop into multiple smaller, independent loops. With a switch, zoning limits which ports can be accessed. Reasons a system administrator, or an application program, would want to limit access include providing security for computer systems, and restricting computer systems access to disk drives with sensitive data. Zoning also allows different computer systems to coexist on the same network. For example, NT devices connected to NT computers can coexist with Unix devices connected to Unix computers. With fabrics, some ports can be shared across zones. As a common port, a tape library could backup both NT and Unix systems. However, this is not possible with loops, due to the nature of how the arbitrated loop protocol functions. Some advantages of zoning include: • Disturbances outside of the zone do not affect devices within the zone. • When backing up to a tape drive, an application will not lose communication with the tape drive when other ports on the system outside of the zone are turned on or off. • Zoning can be done dynamically, allowing an application to select only the devices for communication, which increases the reliability of the overall system. Not all systems and subsystems support zoning. Use of this feature is limited to architectures designed for it. HP Fibre Channel libraries do not need additional features to function in a zoned environment. C- 12 Appendix C