RE: iSCSI: CmdSN during login

[Black_David@emc.com]

Sounds like a good idea to me, and this would also lead to
a definitive resolution of the resource allocation requirements
at targets for immediate commands (which I believe is still
an open issue).  Providing both options just adds complexity,
and I have seen no requests for logins on connections other
than the first to be ordered with respect to other commands
on the first connection.

Thanks,
--David

---------------------------------------------------
David L. Black, Senior Technologist
EMC Corporation, 42 South St., Hopkinton, MA  01748
+1 (508) 435-1000 x75140     FAX: +1 (508) 497-8500
black_david@emc.com       Mobile: +1 (978) 394-7754
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> -----Original Message-----
> From: BURBRIDGE,MATTHEW (HP-UnitedKingdom,ex2)
> [mailto:matthew_burbridge@hp.com]
> Sent: Monday, August 13, 2001 12:35 PM
> To: ips@ece.cmu.edu
> Subject: RE: CmdSN during login
> 
> 
> Could commands sent during the login phase (ie LOGIN + TEXT) 
> be mandatory to
> be immediate and therefore MUST have the I bit set or is 
> there a reason why
> non-immediate login phase commands make sense?
> 
> Cheers
> 
> Matthew Burbridge
> 
> -----Original Message-----
> From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
> Sent: Saturday, August 11, 2001 4:37 PM
> To: ips@ece.cmu.edu
> Subject: Re: CmdSN during login
> 
> 
> There was ambiguity at first login that we have cleared in 
> text and as I
> said I don't see any good reason
> for another case of immediate when we have the immediate bit 
> available.
> What we could do is add anothe pragraph to 8
> recommending when to use the I bit in login.
> 
> Julo
> 
> "Eddy Quicksall" <ESQuicksall@hotmail.com> on 10-08-2001 18:13:32
> 
> Please respond to "Eddy Quicksall" <ESQuicksall@hotmail.com>
> 
> To:   Julian Satran/Haifa/IBM@IBMIL
> cc:   <ips@ece.cmu.edu>
> Subject:  Re: CmdSN during login
> 
> 
> 
> But, what if someone does this without setting the Immediate bit? What
> would
> one do?
> 
> What is wrong with just making the CmdSN not run during 
> login? It seems
> like
> it was an arbitrary choice in the first place since it was originally
> optional and not using it actually worked.
> 
> If CmdSN is stated as only used in FFP, then I don't see any 
> ambiguity.
> 
> Eddy
> ----- Original Message -----
> From: "Julian Satran" <Julian_Satran@il.ibm.com>
> To: <ips@ece.cmu.edu>
> Sent: Friday, August 10, 2001 2:43 AM
> Subject: Re: CmdSN during login
> 
> 
> >
> > Sanjay,
> >
> > If you want to ignore CmdSN and expedite Login processing 
> you can do so
> by
> > having the commands being issued as immediate.
> > This will help us keep away from creating ambiguity about 
> (or another
> > conditional) for when CmdSN is to be used or not.
> >
> > Julo
> >
> > Mark Bakke <mbakke@cisco.com>@ece.cmu.edu on 09-08-2001 23:55:25
> >
> > Please respond to Mark Bakke <mbakke@cisco.com>
> >
> > Sent by:  owner-ips@ece.cmu.edu
> >
> >
> > To:   Sanjay Goyal <sanjay_goyal@ivivity.com>
> > cc:   "Ips (E-mail)" <ips@ece.cmu.edu>
> > Subject:  Re: CmdSN during login
> >
> >
> >
> >
> > Sanjay-
> >
> > I absolutely agree with this; CmdSN is owned by the session, and
> > should not be used until the connection has fully joined 
> the session,
> > which means full feature phase.
> >
> > This should also clean up any ambiguity on when to start
> > using CmdSN.
> >
> > --
> > Mark
> >
> > Sanjay Goyal wrote:
> > >
> > > Hi
> > >
> > >  Assuming Target and Initiator support multiple 
> connections and the
> > session
> > > is having multiple connections. Assuming out-of-order CmdSN is a
> > possibility
> > > for this session.
> > >
> > >  Connection #   1       |       2       |       3
> > > -------------------------------------------------------
> > > Login Cmd  CmdSN=0      |   CmdSN=8     |  CmdSN=9
> > > Txt   Cmd  CmdSN=1      |               |
> > >                                 |               |
> > >                                 |               |
> > > Login Cmd  CmdSN=7      |  CmdSN=10     |  CmdSN=11
> > > -------------------------------------------------------
> > > Data Cmd   CmdSN=12     | CmdSN=14      | CmdSN=15
> > > Data Cmd   CmdSN=13     |               |
> > >                                 |               |
> > >
> > > CmdSN=7 is last of the Login sequence and it is 
> acknowledged by the
> > Target
> > > with "accept login" response.
> > >
> > > Target would receive the PDUs in this CmdSN order
> > >  0 to 7, 8, 9, 12, 10, 11, 13, 14, 15
> > >
> > > Now as Login and Text PDUs are being processed even 
> though you have
> > received
> > > Data Cmd PDUs, you can not pass them to iSCSI layer and 
> hence you are
> > adding
> > > latency.
> > >
> > > What I want to convey from this example is why not use CmdSN just
> during
> > the
> > > FullFeature phase only.
> > >
> > > Regards
> > > Sanjay Goyal
> > >
> > >
> >
> --------------------------------------------------------------
> ------------
> --------------------------
> >
> > >
> > >    Part 1.2    Type: application/ms-tnef
> > >            Encoding: base64
> >
> > --
> > Mark A. Bakke
> > Cisco Systems
> > mbakke@cisco.com
> > 763.398.1054
> >
> >
> >
> >
> 
>