HP Surestore Tape Library Model 10/180 HP Surestore Bridge FC 2/1 LV and FC 4/ - Page 34

Host Device Configuration The host system using a Fibre Channel host bus adapter (HBA) will typically map Fibre Channel devices into the existing device mapping scheme used by that operating system. (Refer to the HBA manual for the mapping table.) The Fibre Channel HBA usually maps Fibre Channel AL_PAs to SCSI target addresses. The HBA will claim enough SCSI bus entries to allow for 125 Fibre Channel targets to map to SCSI bus:target entries. This is usually done by a fixed mapping of AL_PA to bus:target. In such a configuration, the bridge corresponds to a bus:target identifier, with the SCSI devices attached to the bridge appearing as logical units (LUNs). In addition, operating systems can extend the available SCSI limit of 15 Target IDs per bus. Although this is not an issue for the operating system or most applications, there are cases where older applications or Windows NT can have expectations about what are valid SCSI IDs, and not deal correctly with certain mappings. In particular, applications have been seen to exhibit difficulties addressing Target IDs greater than 15 (e.g. 16 and up). This problem can be resolved by configuring the bridge to use hard addressing, and setting the AL_PA used by the bridge to a value that the HBA will map to, with an ID having a value less than 16. 36 Host Device Configuration Chapter 2