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Conference netcad::hub_mgnt

Title:DEChub/HUBwatch/PROBEwatch CONFERENCE
Notice:Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7
Moderator:NETCAD::COLELLADT
Created:Wed Nov 13 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:4455
Total number of notes:16761

3093.0. "Replacing HubManager Module on DH 900 with power ON." by GIDDAY::STANISLAUS () Wed Dec 20 1995 20:19

	I watched the DH900 training video and one of the students asked 
a question - Can the DH900 MAM module be replaced without turning OFF the Hub ?
The answer was NO, you can't. The answer aslo said apart from loosing
configurations you may even damage the module.

	I have been obeying the above rules, until one of my colleagues said
that Ed Buzzel said to him that hot swap of MAM is supported and that neither
damage nor configuration loss will happen.

	So the reason for this note is to clarify answers to two questions:

	1)Will replacing MAM module with power ON ,taking 200% care to insert
the cables correctly, likely (even 1% chance) of damaging the MAM module.

	2)Will some or all flexichannel configurations on the backplane be
intact or lost. I have been told that just configure the new module with the
original modules IP address and mask and IP services module and you are up
and running with no downtime of network. I have been told no configuration will
be lost.

	I personally believe the anser to both the above questions is a NO,
until I heard the name Ed Buzzel from my colleague who said the answer to both
the above questions is YES. Actually two of my colleagues said so.

Alphonse
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3093.1Ed=TruthSCASS1::TERPENINGWed Dec 20 1995 20:355
    If Ed said it, it is true, whatever he says you can take to the bank!
    
    The configurations are stored in the modules, not the MAM.
    
    Regards,
3093.2NETCAD::DOODYMichael DoodyThu Dec 21 1995 10:3918
    The Hub's backplane configuration is stored in the MAM. These are the
    things you set up in Hubwatch's Lan Interconnect screen like the 
    LAN segments and backplane port connections to those lans and whether the 
    FDDI ports point out the front or back. The PortSwitch repeater's front
    panel port assignments to repeater "internal lans" are stored in the
    repeater.
    
    Since the backplane configuration is stored in the MAM, removing the
    MAM from the hub removes the configuration too. When the new MAM card
    is inserted, any existing connections will be deleted.
    
    I don't know what the story is about hot-swapping the MAM card. It
    doesn't sound like a good idea 'cuz I don't think it was designed that
    way. It won't achieve the results you are hoping for because you have
    to re-config... unless you pre-configure the new MAM card in another
    Hub with the exact same modules etc.
    
    -Mike
3093.3HOT-swap of MAM module is not supported or recommended...NETCAD::BATTERSBYThu Dec 21 1995 10:5412
    I wouldn't recommend hot-swapping a MAM module either. There
    are two ribbon cables that attach to the MAM module card. They
    are difficult enough as it is to detach the berg-style connectors
    from the module without invoking some kind of rocking back-and-forth.
    The same thing applies when plugging in the new MAM module and
    mating to these two connectors without also using some rocking motion.
    In both instances one would be verrry likely be making and breaking
    connections to certain pins with power and other signals in a very
    un-controlled manner which would raise the risk of damage to the
    MAM module.
    
    Bob
3093.4MIS-INFORMATIONDELNI::BUZZELLThu Dec 21 1995 16:5831
    
    
    RE: .0
         
       Well since my name has been associated with this MIS-INFORMATION
    let me see if I can set the rcord straight. In any training where
    this topic hasd been discussed my response has always been that you
    should NOT attempt to hot-swap the MAM. I have also used the example
    that Bob uses in .3 as to why it should NOT be done and compare it to
    the reason we ARE ABLE to hot-swap MODULES and POWER SUPPLIES. You
    should schedule down time to replace the MAM.
    
       When the MAM is removed and replaced with a new one ALL
    configuration is LOST. There will be no IP address or backplane
    channel configuration information on the new one. Someone else 
    from Engineering elsewhere in this notesfile answered a question 
    about pre-configuring a new MAM and replacing it for the failed MAM.
    The response was that one could configure a MAM then remove it and 
    place it in another hub and the config would be intact. I have never
    tried this to confirm it.
    
       RE: .3 THANKS. Its things like that that provide energy when one
    has seen home 1 week in 11.
    
       Alphonse would you please have whoever provide you with this
    information contact me so I can understand how anything I said 
    could even remotely be construed to mean you can hot-swap the
    MAM and even more incredibly have  a configuration in the new one.
    
    Ed
    
3093.5more reliable infoNETCAD::CURRIERFri Dec 22 1995 13:1515
    re .4
    
    we have confirmed that a MAM card retains config info when it is moved
    from one hub to another.  i.e.  use HUBwatch to configure the
    backplane; power down the hub; move the MAM card into another
    (posered-down hub); power-up the 2nd hub --  
    
       ASSUMING the 2nd hub contains the SAME modules in the SAME slots
    
    the 2nd hub will have the same config as the 1st
    
    
    -s