Screen only updates on mouse movement

[Mike Miller]

On Wed, 28 May 2008, Elderman, Melvin wrote:

> We have RedHat Linux Enterprise Server 4 with vncserver.
> Our clients are running RedHat Linux Client 4 and have vncviewer 4.0
> Some are on Windows XPSp2 and have the Free edition 4.1
> Due to our systems functionality we cannot easiliy upgrade.
>
> Problem:
> When our clients connect to the server, everything works fine except for
> the screen updates.
> Only when the mouse moves you see a screen update.
> Keyboard input is recieved but it doesnt trigger a screenupdate.
> Now they have to move their mouse continuously while typing.
>
> Does anyone have a sollution besides upgrading?


I don't have the solution, but we are using the same software as you, we 
are not upgrading for the same reason as you, and we have also experienced 
this problem.  Fortunately, our VNC sessions usual work fine for long 
stretches of time and then begin doing what you describe.  Another problem 
is that we sometimes have frozen sessions that have to be killed because 
they are completely unresponsive.  The latter problem seems to be caused 
by port scanning (I'm sure this sensitivity to scanning has been fixed in 
later versions).  I'm not sure what causes your problem with the mouse. 
Is it always present from the beginning when the session is first 
established?  Does it have nothing to do with the port number?

Sometimes I have found that problems are related to ports in the 6000-6100 
range that are used by X and by SSH.  Avoiding 6010, for one, seemed to 
help, and that means avoiding use of VNC with :10 -- 5910.

Let us know if you figure anything out!

Best,

Mike

-- 
Michael B. Miller, Ph.D.
Assistant Professor
Division of Epidemiology and Community Health
and Institute of Human Genetics
University of Minnesota
http://taxa.epi.umn.edu/~mbmiller/