Configuring and Using SCSI Target Mode

The adapter, acting as either a target or initiator device, requires its own SCSI ID. This ID, as well as the IDs of all attached devices on this SCSI bus, must be unique and between 0 and 7, inclusive.

Because each device on the bus must be at a unique ID, the user must complete any installation and configuration of the SCSI devices required to set the correct IDs before physically cabling the devices together. Failure to do so will produce unpredictable results.

SCSI target mode in the SCSI subsystem does not attempt to implement any receive-data protocol, with the exception of actions taken to prevent an application from excessive receive-data-buffer usage. Any protocol required to maintain or otherwise manage the communications of data must be implemented in user-supplied programs. The only delays in receiving data are those inherent in the SCSI subsystem and the hardware environment in which it operates.

The SCSI target mode is capable of simultaneously receiving data from all attached SCSI IDs using SCSI send commands. In target-mode, the host adapter is assumed to act as a single SCSI Logical Unit Number (LUN) at its assigned SCSI ID. Therefore, only one logical connection is possible between each attached SCSI initiator on the SCSI Bus and the host adapter. The SCSI subsystem is designed to be fully capable of simultaneously sending SCSI commands in initiator-mode while receiving data in target-mode.