Virtual TapeServer SCSI-to-FC Adapter User Manual

1-3
Chapter 1: Introduction
Processing SCSI Information
The following section describes how the VT5900-SA processes SCSI information when attached
to FC hosts. Figure 1-5 illustrates steps 1 through 5 of the process.
1. An FC host issues a command. The FC host encapsulates the command in the FCP protocol
and sends the packet to the VT5900-SA.
2. The FC controller in the VT5900-SA receives the packet, interprets the FC information, and
places the packet in buffer memory.
3. The VT5900-SA’s processor interprets the information and programs a SCSI controller to pro-
cess the transaction.
4. The SCSI controller sends the command to the SCSI device (target).
5. The SCSI target interprets the command and executes it.
Figure 1-5. Information processing
6. Data flows between the FC host and SCSI target through payload buffers. See Figure 1-6.
7. Response information flows from the SCSI target back to the FC host. See Figure 1-6.
Figure 1-6. Flow of data and responses
SCSI
Fibre Channel
FC Hosts
SCSI Targets
67
DataResponse