iscsi : iscsi specific CHECK CONDITIONS.

[Santosh Rao <santoshr@cup.hp.com>]

All,

iSCSI specifies that SCSI layer CHECK CONDITIONs be used to indicate
some iscsi specific transport errors such as :

- Unexpected unsolicited data  SK=Aborted Cmd. ASC = 0x0c. ASCQ = 0x0c  
- Not enough unsolicited data  SK=Aborted Cmd. ASC = 0x0c. ASCQ =
0x0d.       
- Protocol Service CRC         SK=Aborted Cmd. ASC = 0x47 ASCQ = 0x05  
- SNACK rejected               SK=Aborted Cmd. ASC = 0x11 ASCQ = 0x13   

However, SPC-2 mandates certain restrictions on when the CHECK CONDITION
scsi status may be used for a REPORT LUNs :
"The device server shall return a CHECK CONDITION only when it is unable
to return the requested LUN inventory" Section 7.19

How should an iscsi target indicate a protocol service crc or SNACK
rejected for a REPORT LUNs command ? Would a CHECK CONDITION generated
as above render iscsi targets SPC-2 non-compliant and break any
functionality w.r.t REPORT LUNs ?

Regards,
Santosh



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Santosh Rao
Software Design Engineer,
HP-UX iSCSI Driver Team,
Hewlett Packard, Cupertino.
email : santoshr@cup.hp.com
Phone : 408-447-3751
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