Siemens PSFR-CP41 - Manual (Page 40)

U42093-J-Z716-1-74 Operating Manual
Configuring the PSFR-CP41 Host Device Configuration
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. This usually results in the Fibre Channel HBA mapping
Fibre Channel AL_PA’s 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 PSFR-CP41 corresponds to a
Bus:Target identifier, with the SCSI devices attached to the PSFR-CP41
appearing as logical units (LUNs). In addition, operating systems can extend the
available SCSI limit of 15 per bus.
Although this is not an issue for the operating system or most applications, there
are cases where older applications can have expectations about what are valid
SCSI ID’s, and not deal correctly with certain mappings. In particular, applica-
tions have been seen to have difficulties addressing target ID’s greater than 15
(e.g. 16 and up). This problem can be resolved by configuring the PSFR-CP41
to use hard addressing, and setting the AL_PA used by the unit to a value that
the HBA will map to an ID with a value less than 16.
For example, depending on the FC HBA, if the hard AL_PA selection is 1, the
address is 1. If the selection is 125, the AL_PA address is 0xEF. Some FC HBA’s
will configure differently, so verify the AL_PA by toggling to hard addressing and
selecting an address.