Subject: RE: iSCSI: DLB [T.31]

From: [email-masked]
Date: Wed, 10 Jul 2002 03:56:48 -0400

Steve,

>  From DLB's comments:
> 
>  >[T.31] 9.16.1  Type
>  >
>  >   An iSCSI target that does not support recovery within connection MAY
>  >   reject the status SNACK with a Reject PDU. If the target supports
>  >   recovery within connection, it MAY reject the SNACK after which it
>  >   MUST issue an Asynchronous Message PDU with an iSCSI event that indi-
>  >   cates "Request Logout".
>  >
>  > This should be conditioned on the operational ErrorRecoveryLevel of the
>  > session, not whether the target supports recovery within connection.
> 
> I would prefer that this not be conditioned on the ErrorRecoveryLevel. If
I 
> am writing code, I may choose to support recovery-within-connection, but 
> not all the features that would be required to move me up to 
> ErrorRecoveryLevel 1. I would like SNACK and Reject PDUs to work properly 
> for my code, even though it is technically only "ErrorRecoveryLevel 0.5".
> 	As I read it, changing the wording would allow the target to ignore
my 
> improved error recovery efforts unless I have a full ErrorRecoveryLevel 1 
> implementation. David, I doubt that is what you intended, so maybe you
want 
> to word it a little differently.

Actually, it was what I intended when I made that comment, BUT, I had not
considered the scenario you describe above ... and so, I now agree with
you.  Therefore I'll withdraw my [T.31] comment provided that the
possibility of multiple "ErrorRecoveryLevel 0.5" levels of support is
described in the overview section to be added on error recovery.

Thanks,
--David
---------------------------------------------------
David L. Black, Senior Technologist
EMC Corporation, 42 South St., Hopkinton, MA  01748
+1 (508) 249-6449            FAX: +1 (508) 497-8018
[email-masked]       Mobile: +1 (978) 394-7754
---------------------------------------------------

---

From: "Julian Satran" <[email-masked]>
Date: Sun, 14 Jul 2002 11:09:25 +0300

The whole text is meant only to show what the normative behavior will be 
at ErrorRecoveryLevel=1 It does not preclude you doing partial recovery
and not raising at level 1 although most of your partners are bound to 
assume the worst and ignore your efforts.

Julo

Steve Reames <[email-masked]>
Sent by: [email-masked]
07/09/2002 11:33 PM
Please respond to Steve Reames

        To:     [email-masked]
        cc: 
        Subject:        iSCSI: DLB [T.31]

                 As I read it, changing the wording would allow the target 
to ignore my

---

From: [email-masked]
Date: Sun, 14 Jul 2002 22:41:08 -0400

We'll need to discuss this in Yokohama, as there seems to be
a difference of opinion about whether this sort of
"ErrorRecoveryLevel 0.5" is allowed.  --David

-----Original Message-----
From: Julian Satran [mailto:[email-masked]]
Sent: Sunday, July 14, 2002 4:09 AM
To: Steve Reames
Cc: [email-masked]; [email-masked]
Subject: Re: iSCSI: DLB [T.31]

The whole text is meant only to show what the normative behavior will be at
ErrorRecoveryLevel=1 It does not preclude you doing partial recovery 
and not raising at level 1 although most of your partners are bound to
assume the worst and ignore your efforts. 

Julo 

07/09/2002 11:33 PM 

        To:        [email-masked] 
        cc:         

> session, not whether the target supports recovery within connection.

I would prefer that this not be conditioned on the ErrorRecoveryLevel. If I 
am writing code, I may choose to support recovery-within-connection, but 
not all the features that would be required to move me up to 
ErrorRecoveryLevel 1. I would like SNACK and Reject PDUs to work properly 
for my code, even though it is technically only "ErrorRecoveryLevel 0.5".
                As I read it, changing the wording would allow the target to
ignore my 
improved error recovery efforts unless I have a full ErrorRecoveryLevel 1 
implementation. David, I doubt that is what you intended, so maybe you want 
to word it a little differently.