Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
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20.15
Recommended Initiator ERP
The Drive's design points for error reporting to the system assumes certain system action for the error return codes.
These assumptions are:
1. SCSI protocol will be the first priority in reporting errors.
2. The system will maintain a log of all reported errors.
3. System architecture should include all error handling recommendations made in this section. Deviations
should have mutual agreement between Drive development and system integration.
This section is directed toward documenting the assumptions made by the Drive that the system is expected to
implement. The two error classes that the system should be concerned with are DATA and NON-DATA errors.
Data errors are those errors that deal with the handling of data to and from the MEDIA and are identified by the
Additional Sense Code contained in the sense data. The Additional Sense Codes for data errors are as follows:
- OC - Write error
- 11 - Unrecovered read error
- 14 - No record found
- 16 - Data Synchronization mark error
- 17 - Recovered read error without LDPC correction
- 18 - Recovered read error with LDPC correction
Typically, data errors do not include positioning of the heads or the data path though the electronics.
Non data errors are those errors that do not have a direct relationship with transferring data to and from the media.
Non data errors can include data handling if the media is not associated with the error (that is, interface error).
The system action assumed for each class of error is outlined here.
20.15.1
Drive Service Strategy
The Drive service strategy is defined so the customer will be able to use the system as soon after a failure is
detected as possible. The first priority is to replace the entire drive to make the system operational with minimal
service time. The service representative should:
1. Back up all the customer data on this drive if possible
2. Replace the complete drive
3. Restore the customer data
4. Return the drive to customer service
20.15.2
Recommendations for System Error Log
The system error log should contain information about the Drive error that will allow recovery actions. The system
error logs should contain all the error information returned in the sense data. At a minimum, the following information
about each error occurrence should be logged.
- Valid bit and error code (Sense byte 0)
- Sense Key (Sense byte 2)
- Information bytes (Sense bytes 3 through 6)
- Command specific information (Sense bytes 8 through 11)
- Additional Sense Code (Sense byte 12)
- Additional Sense Code Qualifier (Sense byte 13)
- Field Replaceable Unit (Sense byte 14)
- Sense Key Specific (Sense bytes 15, 16, and 17)
- Vender Unique error information (Sense bytes 20 through 23)