Virtual TapeServer SCSI-to-FC Adapter User Manual

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Chapter 6: Using Visual Manager
– Link-up Events discovers both the ports and the devices behind the ports for the first link-
up event. Subsequent link-up events will only discover the ports and not the devices
behind the ports.
Manual Discovery (the default selection) sets discovery of new devices to only occur after the
user selects the Discovery option from the Main Menu. With this option, the ports are discov
-
ered but the devices behind the ports are not discovered.
• Buffered Tape Writes enables/disables the Buffered Tape Writes option. When enabled, the
Buffered Tape Writes option returns status on consecutive write commands prior to the tape
device receiving data so that performance may be enhanced.
• Buffered Tape Queue Depth sets the Buffered Tape Queue Depth. Select a setting of 0
through 10 from the drop-down list.
• Default Map sets the mapping mode for the current port. Default Map can be set to either
‘Indexed’, ‘Auto-assigned’, or ‘SCC’. The default value for Default Map is ‘Auto-assigned’.
The FC Auto-assigned map contains all the SCSI devices that are attached to the VT5900-SA.
When a new initiator contacts the VT5900-SA through the selected port, it will be able to
access the devices that are in this map by default. For more information about mapping modes,
see Appendix C.
• Performance Mode toggles between 1 and 2 Gigabit Fibre Channel. The default is 1.
• Force FCP Response Code toggles between DISABLED and CPQ HBA for support of
Compaq-specific HBAs #223180-B21 and #120186-001. The default setting is DISABLED.
• Override Settings are provided to enhance interoperability with some storage devices that
require special consideration during setup of the VT5900-SA configuration menus. To access
the Overrides Settings, select the Go button.
Note: SCSI devices attached to a Fibre Channel port need not be mapped as sequential FC LUNs.
If the device in question supports the REPORT LUNS command, then any mapping desired by
the user is acceptable. However, if the device does NOT support the REPORT LUNS command,
the discovery process will stop whenever the LUN scan finds an empty 16-LUN block,
starting on a 16-LUN boundary. If such a block is found, FC Discovery discovers only the LUNs
up to the empty block; LUNs after the empty block are not discovered.
Note: If set incorrectly and the VT5900-SA is plugged into a Loop or Fabric, the unit may receive
Framing errors as a result of the incorrect FC link speed. This setting must be manually set as it is not
auto-negotiating.