Fujitsu MAS3367 Computer Drive User Manual


 
5.2 INIT Error Recovery Methods (Recommended)
C141-E167 5 - 11
5.1.3 Sense data additional information
Bytes 18 to 47 of sense data are defined as a Fujitsu unique field, and indicate the additional
information which is explained below.
(1) IDD SCSI ID
This field shows the SCSI ID of the very IDD which generated the sense data.
(2) CDB operation code
This field indicates the operation code (the value in the first byte of the CDB) of the command where
the error occurred. When sense data are generated without relation to the INIT issuing a command,
this field shows zero.
(3) Detailed information
The information displayed in bytes 20 to 47 of sense data is information defined by Fujitsu for the
specific product for the purpose of analyzing trouble, and the contents of this information are not
made public. However, the user should present this information to the persons in charge at Fujitsu as
troubleshooting and repair information collected in error logging (shown in Section 5.3.3) of all the
bytes in sense data, including this field.
5.2 INIT Error Recovery Methods (Recommended)
When a single command or a series of linked commands are not terminated with a GOOD status or
TASK COMPLETE message reported, the INIT should execute error recovery processing
corresponding to the state in which the command was terminated. Here, the procedure for analyzing
the command execution termination state and recommended procedures for error recovery
processing executed by the INIT in accordance with the results are explained.
5.2.1 Termination status analysis and error recovery methods
Figure 5.3 shows a model of the INIT's general processing flow from issuing of the command until
reception of the termination status. In the figure, a "BUS FREE Error" is the case where the SCSI
bus entered the BUS FREE phase at a point not intended by the INIT (at a point when entering the
BUS FREE phase was not permitted by the SCSI bus protocol specification), and normally, it is an
error detected by the host system's (INIT's) SCSI controller's hardware or firmware.