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    RE: ISCSI: Error Recovery Level 0



    But devices supporting level 0 are not allowed to attempt any of the other recovery methods.
    
    It appears from reading the text for digest recovery, if a header disgest error occurs, that I just throw away the PDU. If the pduLength was corrupted, then I am now out of sync. Do I wait for the initiator to drop the connection?
    
    The flow for a data PDU is simple enough.
    
    So the error recovery, "incremental requirement description" is misleading.... no real data PDU transmissions are required. The target can just request logout.... Correct?
    
    Kevin
    
    -----Original Message-----
    From: Mallikarjun C. [mailto:cbm@rose.hp.com]
    Sent: Wednesday, May 29, 2002 2:46 PM
    To: ips@ece.cmu.edu
    Subject: Re: ISCSI: Error Recovery Level 0 
    
    
    Kevin,
    
    From: "LEMAY,KEVIN (A-Roseville,ex1)" <kevin_lemay@agilent.com>
    > I have the following question on error Recovery level 0.
    >
    > On page 105, v12, it says that error recovery level 0 must perform Session recovery as described in 6.12.4.
    
    I can't find it.
    
    It's only saying that the minimally expected error recovery capabilities for level 0 are as described
    in 6.12.4, not that session recovery must be performed for every error....
    
    If you look in 6.12.4, it specifically states that session recovery is done only if all other recovery
    attempts fail.
    
    >
    > This seems to imply that:
    > If I have a multi-connection session were one connection experiences a digest error, then I must close all
    connections on the session, even killing IOs over the good connection.
    >
    > This is absurd!
    
    Indeed it would be if so implemented (even while it's legal).
    
    >Why not just close the one connection that has a problem and allow the IO to be restarted on one of the other
    live connections? There is nothing wrong with the session, only a single connection.
    
    That's a reasonable recovery strategy (if it's a SCSI restart).
    --
    Mallikarjun
    
    Mallikarjun Chadalapaka
    Networked Storage Architecture
    Network Storage Solutions
    Hewlett-Packard MS 5668
    Roseville CA 95747
    cbm@rose.hp.com
    
    
    >
    > I guess I am calling for a level 0.5, so that I can abort only the troublesome connection. This would allow
    for a much faster IO recovery without adding hardly any coding complexity that is required for level 1.
    >
    > Comments?
    >
    > Kevin Lemay
    >
    


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Last updated: Wed May 29 20:18:37 2002
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