Temperamental VNC

[NoOp]

On 09/01/2010 03:33 PM, Michael Pavling wrote:
> I've been getting an annoying problem on a new machine I've set up.
> It's running Ubuntu 10.04.1 AMD64 desktop, but is "headless". If I ssh
> onto it and launch VNCserver (I've installed TightVNC) I can log on
> and it works fine for a time. But at some point - generally when I
> click a button in VirtualBox, the VNC viewer closes on my PC, and in
> my ssh window, I can see that the VNC server process has died.
> Starting a new vncserver starts on a new port (as there are still
> locks in /tmp from the previous process).
> 
> Any idea what's causing VNC to die? Or is there a better/different way
> to administer a headless machine (I'm temporarily using remote desktop
> to avoid the process terminations, but I have to be logged in on the
> console for it to work, which isn't acceptable long term - I need to
> be able to reboot without concern)

I'll forget the VRDP bit & just let you know that after trying to
duplicate your problem, I've found that VNC and VirtualBox doesn't seem
to want to play well together. Here is the prelim:

1. I've two machines/desktops w/monitors side-by-side, both running
10.04 (gnome desktops) and VirtualBox PUEL 3.2.6 r64453 (32bit) with
Win2KPro guests.

2. I VNC to desktop B and start a VM Win2KPro session. The session will
start, but then goes to 98% CPU and the session stalls (grey desktop).
VNC doesn't die, but the VM session stalls out completely.

3. I kill the VNC session from desktop A and get to the Win login on
screen on B. Once I log into the Win VM session (using the keyboard
etc., directly on machine B), I can restart VNC from desktop A and work
in desktop B's VM guest.

I notice that it's not vino-server or VirtualBox that is eating hte cpu
cycles, but Xorg. Xorg (when the VM is working OK w/VNC is sucking up to
83% CPU (2.4Ghz Intel processor). If I kill VNC on desktop A, Xorg drops
to about 3.7% on desktop B (with the VM running. Fire VNC back up on
desktop A to desktop B and Xorg 80+ percent CPU.

I'll see if I can find time to explore further. But so far, in this
case, I see Xorg as being the possible culprit with both VirtualBox and
vino-server behaving quite well. While you are ssh'ed into the machine,
run top & see if you get the same/similar.