HP Surestore Tape Library Model 2/28 HP SureStore Fibre Channel SCSI Bridge 21 - Page 69
Laser Power Control Systems, Device Addressing
View all HP Surestore Tape Library Model 2/28 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 69 highlights
Fibre Channel Overview Problems with Fibre Channel Laser Power Control Systems There are two types of systems approved for use: OFC and non-OFC. These two types of control systems can exist on the same network, but are not optically compatible and cannot be hooked up to the same optical cable. Device Addressing The two modes of addressing used in Fibre Channel, included on page A-7, are hard and soft addressing. In small, controlled environments, hard addressing works well. Also, some operating systems and host bus adapters do not support soft addressing. Large Fabric networks, connecting many devices, require the flexibility of soft addressing; hard addressing is not supported in a Fabric environment. HBA drivers cannot dynamically track device addresses that can change after the system is turned on. Physical addresses change while the operating system uses the same logical name for the device. Applications that always use the same physical device may use the World-Wide Name (WWN). For example, backup programs must locate the library and all of its drives regardless of the bus address. Fibre Channel resolves these issues. Proper system planning and research prior to installing a Fibre Channel system will help avoid these problems. Configured properly, Fibre Channel is as reliable and easy to use as current SCSI systems. Fibre Channel Overview Appendix A A- 11