Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
304
20.1.6
Command Processing During Startup and Format
Operations
If the Target receives a command from an Initiator while the Target is executing a startup or format operation, the
response of the Target varies with the command as follows:
INQUIRY
The drive sends inquiry data and returns appropriate status.
REQUEST SENSE
Executes the command, returns a Sense key of NOT READY and an Additional Sense Code
of LOGICAL UNIT NOT READY and returns GOOD STATUS.
The Additional Sense Code Qualifier that is returned depends on type of I/O processes that
are active:
For the START/UNIT STOP and the Auto-start operation, the qualifier returned is LOGICAL
UNIT IS IN PROCESS OF BECOMING READY. For the FORMAT UNIT command, the
qualifier returned is LOGICAL UNIT NOT READY, FORMAT IN PROGRESS, and the Sense
key specific bytes are set to return the progress indication.
REPORT LUNS
The drive sends REPORT LUNS data and appropriate status.
ALL OTHER
The drive terminates the command with CHECK CONDITION status. The Sense data
generated is described in Request Sense above.
20.1.7
Internal Error Condition
The Target generates an Internal Error condition for all Initiators when an internally initiated operation ends with an
unrecoverable error, that is, the startup sequence for Auto Start enabled terminates after the SCSI bus has been
enabled and prior to completion of the bring-up sequence.
An Internal Error condition causes Sense data to be generated and saved for all Initiators. The Error Code field of the
Sense is set for a Current Error (70h or 72h) and the Sense Key is set to HARDWARE ERROR. Recovered errors
are not reported.
The Internal Error condition persists for each Initiator until that Initiator clears the condition from the logical unit as
described below. Several commands are handled as special cases during an Internal Error condition. These cases
are also discussed.
If the Target receives a command from an Initiator while an Internal Error condition exists for that Initiator, the
response of the Target varies with the command as follows:
INQUIRY
The drive executes the command with GOOD status and does not clear the Internal Error
condition.
REQUEST SENSE
The drive executes the command, returns the sense data generated by the Internal Error
condition, returns Good Status, and clears the Internal Error condition for that Initiator.
ALL OTHER
The drive terminates the command with a CHECK CONDITION status and clears the Internal
Error condition.
20.1.8
Deferred Error Condition
Error code (71h or 73h) of sense data indicates that the Check Condition status returned is the result of an error or
exception condition that occurred during execution of a previous command for which Good status has already been
returned.
The drive creates an Deferred Error condition when
- Execution of a Format Unit command with the immediate bit of one ends with an error.
- Execution of a Write command with WCE (Write Cache Enable) bit of one ends with an error.