RE: Comments on iSCSI -03

[julian_satran@il.ibm.com]

Elliott,

There seems to be a requirement in SAM to send the SCSI event indicator and
as you point out
a discrepancy with SPC.

I would appreciate if one of the T10 luminaries would comment.

Julo

"Elliott, Robert" <Robert.Elliott@compaq.com> on 30/01/2001 17:42:06

Please respond to "Elliott, Robert" <Robert.Elliott@compaq.com>

To:   Julian Satran/Haifa/IBM@IBMIL, Charles Binford
      <Charles.Binford@BlueSpruceNet.com>, ips@ece.cmu.edu
cc:
Subject:  RE: Comments on iSCSI -03




> [cb-09] page 57
> Two problems with the following list; 5 & 6 should be 4 & 5,
> and item number 3 is not in SAM-2 r15 (the latest version
> I could find).  Was something recently added?  Again, I
> believe the new Task Aborted Status solves the problem.
>
> 2.17.2 SCSI Event Indicator
>
>   The following values are defined.  (See [SAM2] for details):
>
>      1    An error condition was encountered after command
>      completion.
>      2    A newly initialized device is available to this initiator.
>      3    All Task Sets are being Reset by another Initiator
>      5    Some other type of unit attention condition has occurred.
>      6    An asynchronous event has occurred.

><js>numbering will be fixed. I will be glad to change/elliminate
> 3 to task aborted if I get a good pointer and it is good for
> commands in flight -=
>
> meanwhile would it be fair to say that it is subsumed by 6 </js>

Julian, according to your message on 4 Jan copied below, the
SCSI Event reasons are going to be eliminated altogether.
The sense data contains the most accurate information
about which event occurred.

---
PC: Robert.Elliott@compaq.com
UNIX: relliott@unixmail.compaq.com

Previous message:
To: "Elliott, Robert" <Robert.Elliott@compaq.com>
Subject: Re: iSCSI: SCSI Event Indicator
From: julian_satran@il.ibm.com
Date: Thu, 4 Jan 2001 09:55:06 +0200
cc: ips@ece.cmu.edu
Sender: owner-ips@ece.cmu.edu


Will do,

Thanks,
Julo

"Elliott, Robert" <Robert.Elliott@compaq.com> on 03/01/2001 19:00:58

Please respond to "Elliott, Robert" <Robert.Elliott@compaq.com>

To:   "'ips@ece.cmu.edu'" <ips@ece.cmu.edu>
cc:
Subject:  iSCSI: SCSI Event Indicator




The Asynchronous Event data structure includes an "iSCSI Event
Indicator" field and a "SCSI Event Indicator" field.  The iSCSI
field indicates iSCSI-specific causes, which is fine.  The SCSI
Event field indicates generic SCSI causes.

I suggest removing the SCSI Event Indicator values.  The
information is contained within the sense data itself.

The SEND command in SPC-2, the current mechanism to report
Asynchronous Events, does not include an Event field like this.

I suggest simplifying the field to:
    0 = not a SCSI Event
    1 = SCSI Event

This is the text in iSCSI revision 02, with comments
listing where in the sense data that information is
communicated:

   2.17.2 SCSI Event Indicator

   The following values are defined.  (See [SAM2] for details):

      1    An error condition was encountered after command
      completion.
[Sense data RESPONSE CODE field is DEFERRED ERRORS - 71h]

      2    A newly initialized device is available to this initiator.
[Sense data ASC/ASCQ is REPORTED LUNS DATA HAS CHANGED]

      3    All Task Sets are being Reset by another Initiator
[Sense data ASC/ASCQ is COMMANDS CLEARED BY ANOTHER INITIATOR]

[where is 4?]

      5    Some other type of unit attention condition has occurred.
[Sense data SENSE KEY field is UNIT ATTENTION - 6h]

      6    An asynchronous event has occurred.
[Any other sense data]

   Sense Data accompanying the report identifies the condition.  The
   Length parameter is set to the length of the Sense Data.

   For new device identification an iSCSI target MUST support the Device
   Identification page.


The list was probably taken from this list in SAM-2; however, it's
not an exact match:

    Asynchronous Event Reporting is used to signal a device that
    one of the four events listed below has occurred:
    a) an error condition was encountered after command completion;
    b) a newly initialized device is available;
    c) some other type of unit attention condition has occurred; or
    d) an asynchronous event has occurred.

---
PC: Robert.Elliott@compaq.com
UNIX: relliott@unixmail.compaq.com