Incorrect Initiator Connection; Command Processing During Execution Of Active I/O Process - Hitachi HUS151473VL3800 - Ultrastar 73.4 GB Hard Drive Specifications

20.1.2.3 Case 3 - After selection message sequence
It is permissible for the initiator to issue multiple IDENTIFY messages during a single command sequence provided the LUN
remains the same. If the LUN is altered, the drive goes to a Bus Free Phase.

20.1.3 Incorrect Initiator Connection

Incorrect Initiator Connection error is reported if any of the following conditions occur:
• an Initiator attempts to establish an I_T_L nexus when an I/O process (either queued or active) with an I_T_L nexus
already exists from a previous connection with the same Initiator.
• an Initiator attempts to establish an I_T_L_Q nexus when an I_T_L nexus already exists from a previous connection
with the same Initiator.
• an Initiator attempts to establish an I_T_L nexus when an I_T_L_Q nexus already exists from a previous connection
with the same Initiator.
Note: It is not an Incorrect Initiator Connection to send a command without a Queue tag message when sense is
pending on the logical unit for the Initiator that issues the REQUEST SENSE command. (If the command is not
REQUEST SENSE or INQUIRY, sense data is cleared upon receipt of the command.)
• an Initiator attempts to establish an I_T_L_Q nexus when an I/O process (either queued or active) when an I_T_L_Q
nexus already exists from a previous connection with the same Initiator.
If any of the above errors occur, all queued I/O processes and active I/O processes associated with the issuing Initiator on the
specified logical unit are terminated. The current I/O process is ended with a Check Condition status, the sense key is set to
Aborted Command, and the additional sense code is set to Overlapped Commands Attempted. Status is only returned for the
current I/O process.

20.1.4 Command Processing During Execution of Active I/O Process

When the Target is not executing any active I/O processes, a new I/O process is permitted to execute (unless execution is pre-
vented by another internal Target condition listed in Section "Priority of SCSI Status Byte Reporting" on page).
If an active I/O process does exist when the Target receives a new command, then the Target determines if
• Check Condition Status with Sense Key = Aborted Command is returned for an Overlapped Commands Attempted
error
• the command is permitted to execute
• the command is added to the command queue
• Queue Full Status is returned
• Busy Status is returned
If an active I/O process does exist when the Target receives a new command, 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 and the additional sense code set to
Overlapped Commands Attempted
- See Section 20.1.3, "Incorrect Initiator Connection" on page 228.
• 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 startup operation or format
operation is an active process.
• the command is permitted to execute if the conditions to execute concurrently are met. (See Section 20.5, "Concur-
rent I/O Process" on page 241)
• the command is added to the command queue for an I_T_L nexus if all the following conditions exist:
Hitachi Ultrastar 15K147 SCSI Hard Disk Drive Specification
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