Queue Full Status is returned
Busy Status is returned
If an active I/O process does exist when the Target receives a new command, then the Target determines
how the new command should be handled based on the following rules:
Check Condition Status is returned with Sense Key set to Aborted Command for an Overlapped Com-
mands Attempted error if:
− See 10.1.3, “Incorrect Initiator Connection” on page 180
the command is permitted to execute if
− the command is an Inquiry or Request Sense command
Check Condition Status is returned with Sense Key set to Logical Unit Not Ready if:
− the start-up operation or format operation is an active process.
the command is permitted to execute if
− the conditions to execute concurrently are met. (See 10.5, “Concurrent I/O Process” on page 189)
the command is added to the command queue for an I_T_L nexus if:
− no Queue Tag message was received during the connection which
established the I/O process,and
− disconnection is allowed for the current I/O process, and
− there is no queued I/O process or active I/O process corresponding to the
I_T_L nexus for the current I/O process, and
− the command is not linked to a previous command.
the command is added to the command queue for an I_T_L_Q nexus if:
− a Queue Tag message was received during the connection which
established the I/O process, and
− Tagged Queuing is enabled(DQue = 0), and
− an I/O process(either active or queued) exists at the Target for this
Initiator, and
− disconnection is allowed for the current I/O process, and
− there is no queued I/O process or active I/O process corresponding to the
I_T_L_Q nexus for the current I/O process, and
− the command is not linked to a previous command.
Queue Full Status is returned if:
− the command would otherwise be queued (according to the rules described
above) but the command queue is full and all slots are utilized, or
− the command would otherwise be queued (according to the rules described
above) but all of the available command queue slots not reserved for use
by another initiator are utilized, or
− Tagged Queuing is enabled(DQue = 0) and a Format Unit command was
previously queued but has not yet begun execution, or
− Tagged Queuing is enabled(DQue = 0) and a Start Unit command was
previously queued but has not yet begun execution.
Busy Status is returned if:
− Tagged Queuing is disabled(DQue = 1) and a Format Unit command was
previously queued but has not yet begun execution, or
− Tagged Queuing is disabled(DQue = 1) and a Start Unit command was
previously queued but has not yet begun execution, or
Additional Information 181
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