RE: iSCSI: Login Redirect

["Rajkumar Velpuri" <rajkumar.velpuri@intransa.com>]

The Gilligan draft submitted to IPS working group in March describes
using login re-direct for load balancing and failure recovery.

The proposal in Gilligan draft was addressing issues not described in
iSCSI draft.  I believe Lakshmi's question fits into that context.

Raj Velpuri

-----Original Message-----
From: Mallikarjun C. [mailto:cbm@rose.hp.com] 
Sent: Tuesday, July 15, 2003 10:14 AM
To: Lakshmi Ramasubramanian; ips@ece.cmu.edu
Subject: Re: iSCSI: Login Redirect

If this mis-direction is going on to different portals within
the same target node, I would think that it implies a serious
configuration issue within the target node because it either
does not have a global node-level view of the iSCSI service
it offers, or the situation is changing too rapidly to be correct.

If on the other hand, this mis-direction is forcing an 
initiator to shuttle to different target nodes, it usually implies a
lack of a consistent SAN-level view among the target nodes
that are supposed to be doing cooperative redirection (which
is what the feature was meant for).

In either case, I tend to think that the issue is one of implementation/
configuration and placing hard limits on the # of redirections in
the spec is neither reasonable nor enforceable.   I believe that the 
spec doesn't preclude implementations from having a limit (for ex., the 
initiator iSCSI may decide to give up the chase after X attempts and 
report a failure to its ULP).
--
Mallikarjun

Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions
Hewlett-Packard MS 5668 
Roseville CA 95747
cbm@rose.hp.com

----- Original Message ----- 
From: "Lakshmi Ramasubramanian" <nramas@windows.microsoft.com>
To: <ips@ece.cmu.edu>
Sent: Tuesday, July 15, 2003 8:51 AM
Subject: iSCSI: Login Redirect


When a target is moved (Temporary or Permanent), target
sends an appropriate status code and gives the new target
address. Is there a limit on the number of times a target
can redirect login? If not, should we have one?
 
    Initiator logs into Portal A. 
    Target redirects to Portal B.
    Initiator logs into Portal B. 
    Target now redirects to Portal C.
    And so on...
 
Should we have an upper limit on the number of times a target
can redirect the login?
 
thanks!
 -lakshmi