Re: iSCSI:Clear Task Set

["Julian Satran" <Julian_Satran@il.ibm.com>]

John,

The LUN is just a mistake there - in all three instances it should be LU.
The definitions are in accordance with SAM . There are two task management 
modes - tasks sets-per-initiator at each LU or common for all initiators. 
The mode is a SCSI issue controlled by a field in the Control-Mode page.
Clear task set MAY clear all the tasks in the task set - even if common to 
all initiators if that is the way the task set is managed. That is also 
the difference between clear-task-set and abort task set.

Julo







John Hufferd@IBMUS
23-11-01 11:29

 
        To:     Julian Satran/Haifa/IBM@IBMIL@IBMDE
        cc:     ips@ece.cmu.edu
        From:   John Hufferd/San Jose/IBM@IBMUS
        Subject:        iSCSI:Clear Task Set

 

Julian, and List  (using v 0.9)
In point 9.4, just before 9.5  the Table entry associated with Clear Task 
Set applies to:

"All tasks associated with the specified LUN and initiator. For all other 
initiators all tasks at LUN with no regard to order."

Perhaps we mean LU here, but I know that the iSCSI layer does not have 
information about LU, only about the LU Number (LUN) in the command.  We 
can not tell, at the iSCSI layer, if the  LU represented  by a LUN on 
Session 1, has any relationship to any LUN on any other session.

This is because each initiator may have their own numbering for LUs. 
Therefore, do we just pass the Clear Task Set to the SCSI layer and hope 
for the best, or does the iSCSI layer also suppose to apply the Clear Task 
Set to all the sessions that it has coming into the iSCSI (SCSI) Target 
Port?  If the latter, again how will that work when the iSCSI layer has no 
idea what LU an Initiator's LUN will map to?
.
.
.
John L. Hufferd
Senior Technical Staff Member (STSM)
IBM/SSG San Jose Ca
Main Office (408) 256-0403, Tie: 276-0403,  eFax: (408) 904-4688
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