SCSI Status Code
A SCSI Status Code is used to determine the success or failure of a SCSI command. At the end of any command, the target returns a Status Code byte which should be one of the following:
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[edit] 00h OK
This status code indicates that the device has completed the task successfully.
[edit] 02h Check condition
When the target returns a Check Condition in response to a command it is indicating that it has entered a contingent allegiance condition. This means that an error occurred when it attempted to execute a SCSI command. The initiator usually then issues a SCSI Request Sense command in order to obtain a Key Code Qualifier (KCQ) from the target.
[edit] 04h Condition Met
This status code is returned on successful completion of a Search Data command or a Pre-fetch Command.
[edit] 08h Busy
The target returns Busy if it cannot complete a command at that time, for example if it is in the contingent allegiance condition.
[edit] 10h Intermediate
The target returns Intermediate when it successfully completes a linked command (except the last command).
[edit] 14h Intermediate - Condition met
As the name suggests, this status code is simply a combination of 10h Intermediate and 04h Condition Met.
[edit] 18h Reservation conflict
The target returns this status code if an initiator attempts to access a LUN that has been previously reserved by another initiator using the Reserve or Reserve Unit command.
[edit] 22h Command terminated
The target returns this status if the target has to terminate the current I/O process because it received a Terminate I/O Process message. This status code is obsolete as of SAM-3.
[edit] 28h Queue (task set) full
Similar to 08h Busy status, this status code is returned when the logical unit lacks the resources to accept a received task from an I_T nexus. This status code implies that the logical unit already has at least one task from that I_T nexus, where the 08h Busy status code implies that the logical unit currently has no tasks from that I_T nexus.
[edit] 30h ACA active
The target returns this status code if an auto-contingent allegiance condition has occurred.
[edit] 40h Task aborted
The target returns this status code when a task is aborted by another I_T nexus and the TAS bit in the Control mode page is set to one.
[edit] References
SAM-4 clause 5.3.1
