Virtual TapeServer SCSI-to-FC Adapter User Manual

4-1
Chapter 4
Addressing and Logical Unit Management
To provide connectivity between hosts and devices, it is necessary for the VT5900-SA to establish
itself with an address on each connected Fibre Channel network and SCSI bus.
SCSI Bus Configuration
The VT5900-SA provides the capability to reset SCSI buses during the VT5900-SA boot cycle.
This allows the devices on a SCSI bus to be in a known state. Configuration provides for the SCSI
bus reset feature to be enabled or disabled. The feature is enabled in the default configuration but
should be disabled for configurations using tape changers or other devices that have long reset
cycles, or are adversely affected by bus resets.
The VT5900-SA negotiates for the maximum values for transfer rates and bandwidth on a SCSI
bus. If an attached SCSI device does not allow the full rates, the VT5900-SA will use the best rates
it can negotiate for that device. Negotiation is on a device specific basis, so the unit can support a
mix of SCSI device types on the same SCSI bus.
FC Port Configuration
By default the configuration of the FC ports on the VT5900-SA is set to Auto Sensing to detect
whether an Arbitrated Loop or Switched Fabric is used. However, in situations where another FC
device such as a switch is also using auto sensing for FC ports, the FC port configuration of the
VT5900-SA must be manually set to N_Port mode. As an example, if there is a switch or other
device using U-ports on a fabric, the VT5900-SA must be manually set to use N_Port mode. In
addition, the switch itself must be configured for F-Port. For more information, see the Fibre
Channel Configuration sections in “
Chapter 5, VT5900-SA Management” and “Chapter 6, Using
Visual Manager.”