[AG-TECH] KVMs for AG?

Tom Coffin tcoffin at ncsa.uiuc.edu
Fri May 3 14:01:46 CDT 2002

At ACCESS, we have been using VNC to manipulate our presenter laptop (the 
loading of slides and various presentations) it's very effective.
Havn't tried it on the a or v machines but it sounds like a do-able 
option. note: we havn't had any kvm crashes since we have started 
backing off on the mouse and keyboard input during switching.

I would like to see how VNC can handle the multiple outputs of the
display machine. Anybody experiment with that yet?

At 02:25 PM 5/3/2002 -0400, Rob Ellison-Potter wrote:
   >Has anybody had some positive experiences using VNC as a work around to
   >this. I.E., VNC to your other machines so you don't have to use the KVM.
   >Robert Ellison-Potter
   >Jr. Network Administrator
   >SC-31 US Dept of Energy
   >rellisonpotter at er.doe.gov
   >----- Original Message -----
   >From: "Mike Weaver" <weaver at er.doe.gov>
   >To: "Don Morton" <morton at cs.umt.edu>; "Tom Coffin" <tcoffin at ncsa.uiuc.edu>
   >Cc: <ag-tech at mcs.anl.gov>; <bernholdtde at ornl.gov>
   >Sent: Wednesday, April 03, 2002 11:32 AM
   >Subject: Re: [AG-TECH] KVMs for AG?
   >> The Belkin manual mentions (in small print) in a couple of places not to
   >> move the mouse or use the keyboard when switching channels and that the
   >> mouse will be unresponsive for 1-2 seconds after a switch.  We try to be
   >> careful about this as possible!  It also states not to use the
keyboard or
   >> mouse on the active channel if the computer is booting as this can cause
   >> computer not to see the device.
   >> That being said, I can reboot a working machine on channel 1, switch to
   >> channel 2, wait exactly 5.2371 seconds, work on channel 2 for a while
   >> switch back to channel 1.  Wait another 5.2371 seconds and find that the
   >> keyboard (or sometimes mouse) doesn't work.  I know that mouse
   >> synchronization in particular is a very difficult problem for KVM
   >> but I do not see these kinds of problems on other brands ( we also use
   >> and Avocent/Cybex).
   >> Mike
   >> ----- Original Message -----
   >> From: "Don Morton" <morton at cs.umt.edu>
   >> To: "Tom Coffin" <tcoffin at ncsa.uiuc.edu>
   >> Cc: "Mike Weaver" <weaver at er.doe.gov>; <ag-tech at mcs.anl.gov>;
   >> <bernholdtde at ornl.gov>
   >> Sent: Wednesday, April 03, 2002 9:49 AM
   >> Subject: Re: [AG-TECH] KVMs for AG?
   >> > Tom Coffin wrote:
   >> > >
   >> > > I have noticed that with these switches they somtimes
   >> > > freeze the mouse and keyboard if you are sending mouse
   >> > > commands while switching.
   >> > > I was recently putting our switch through some rugged testing
   >> > > and figured that I really need to be patient or use a
   >> > > slower process while switching. I now make sure that I am not
   >> > > touching the mouse while switching. Let me know if the mouse
   >> > > and keyboard still freeze while trying this movement.
   >> > > Not a solution - but a workaround...
   >> >
   >> > yep, completely unscientific analysis and fix but, same
   >> > situation here :)  i've found that it takes a few seconds
   >> > for the electrons to switch between two machines and, once
   >> > i actually do the keyboard switch, if i wait about
   >> > 5.2371 seconds, then i can usually start moving the mouse
   >> > without having things freeze up on me.  so, i'm being
   >> > sarcastic but, it IS true that just waiting several
   >> > seconds before moving the mouse typically reduces the
   >> > chance of a freeze up.
   >> > --
   >> >    Don Morton                   http://MRoCCS.cs.umt.edu/~morton/
   >> >    Department of Computer Science       The University of Montana
   >> >    Missoula, MT 59812 | Voice (406) 243-4975 | Fax (406) 243-5139

Tom Coffin .......................... tcoffin at ncsa.uiuc.edu

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