User Manual

SCSI Commands Reference Manual, Rev. J 148
www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)
3.20.8 Error history mode (1Ch)
3.20.8.1 Error history overview
This mode is used to manage and retrieve error history (see SPC-5).
If the device server is unable to process a READ BUFFER command with the
MODE field set to 1Ch because of a vendor specific
condition, then the device server shall terminate the READ BUFFER command with CHECK CONDITION status, with the sense key
set to ILLEGAL REQUEST, and the additional sense code set to COMMAND SEQUENCE ERROR.
The BUFFER ID field (see table 109) specifies the action that the device server shall perform, and the parameter data, if any, that
the device server shall return.
The command shall be terminated with CHECK CONDITION status with the sense key set to ILLEGAL REQUEST and the additional
sense code set to OPERATION IN PROGRESS if the device server receives a READ BUFFER command:
a) with the MODE field set to 1Ch;
b) with the BUFFER ID field set to a value that table 109 shows as constrained by error history I_T nexus;
c) if an error history I_T nexus exists and the command is received from an I_T nexus that is different that I_T nexus; and
d) an error history snapshot exists.
BUFFER OFFSET field
The BUFFER OFFSET field specifies the byte offset from the start of the buffer specified by the BUFFER ID field from which the device server shall
return data. The application client should conform to the offset boundary requirements indicated in the READ BUFFER descriptor
(see 3.20.5). If
the buffer offset is not one of those shown in table 109 or the device server is unable to accept the specified buffer offset, then the device
server shall terminate the READ BUFFER command with CHECK CONDITION status, with the sense key set to ILLEGAL REQUEST, and the addi-
tional sense code set to INVALID FIELD IN CDB.
Table 109 Error history BUFFER ID field
Code Description Buffer offset
Error history
I_T nexus
constrained
Reference
00h
Return error history directory
0000h Yes 3.20.8.2
01h
Return error history directory and create new
error history snapshot (see 1.1 and SPC-5)
0000h Yes 3.20.8.2
02h
Return error history directory and establish new
error history I_T nexus (see 1.1 and SPC-5)
0000h No 3.20.8.2
03h
Return error history directory, establish new
error history I_T nexus, and create new error his-
tory snapshot
0000h No 3.20.8.2
04h to 0Fh
Reserved
Yes
10h to EFh
Return error history
0000h to FFFFh Yes 3.20.8.3
F0h to FDh
Reserved
Yes
FEh
Clear error history I_T nexus
Ignored Yes 3.20.8.4
FFh
Clear error history I_T nexus and release error
history snapshot
Ignored Yes 3.20.8.5