HP Surestore Tape Library Model 20/700 HP Surestore Bridge FC 2/1 LV and FC 4/ - Page 40

The indexed addressing table has the structure shown in Table 7 on page 41. The bridge will allow up to 80 device entries to be mapped. The index table can be manually edited and is then saved to the bridge FLASH memory. The Configuration menu has options allowing the table to be filled in order of increasing bus, target ID, or LUN, as may be desired for the specific requirements needed. Options are also provided to perform SCSI device discovery and fill the table in the order that devices are discovered on a SCSI bus. Indexed addressing mode is recommended for environments where SCSI device configuration may change, and a fixed mapping from the application to the target device is required. That is, if a SCSI device is removed from the SCSI bus, and the bridge is power cycled, then the FC-to-SCSI addressing for the remaining SCSI devices will not change and the SCSI devices can be replaced at the same address. An example of such an environment is where hot-pluggable devices may be used, thereby changing the order of devices on a SCSI bus. Auto Addressing The auto addressing option is similar to indexed addressing. However, the table used is created each time through SCSI device discovery upon power-up (or other bridge initialization process), and is not retained. As the bridge performs device discovery on a SCSI bus, the table is filled with adjacent FCP LUNs, referencing each subsequent SCSI device. The host system then detects every attached device without voids, allowing full device discovery to the host. This allows easy configuration in environments where device ordering is not important, and hot plugging of SCSI devices will not occur. Configuration allows for discovery to be performed in order of bus, target ID or LUN, as desired for the specific environment. In auto addressing, bus number order is configured as the default mode on the bridge. 42 Address Mapping Chapter 2