virtualbox.org

Everything seems to be working, with an anomaly...

I have 4 host machines, two Windows 7 and two Windwos 8, all 64-bit. I've created and installed (not cloned - full create and install) Ubuntu 13.04 guest VMs on all of them. On 3 of them everything is fine. On the newest one, an i7 laptop with an nVidia 660M using the newest WHQL driver, I see a "phantom" window when 3D acceleration is enabled for the guest titled "Chromium render spu" when using a 3D session (like Unity). In addition, if I run it fullscreen, I don't have the mini bar and ctrl-home doesn't work (which is an old problem with VirtualBox and Ubuntu that I've learned to deal with). The final problem is that if I can minimize the window (usually by ctl-alt-delete, run task manager) and then bring the VM to the foreground again, I have to click the screen once to get it to actually render, like maybe there's a focus issue. It seems to be running with acceleration - the Unity interface is fast and shows 3D acceleration.

My biggest question is what is that phantom window, and why do I see it only on this one machine? I feel if that gets resolved, the other weirdnesses might go away... my gut feeling is that this is indicating software rendering on the host somehow.

EDIT: Forgot - the problematic laptop is using VBox 4.2.16 with extension pack installed, and the guest additions installed in the guest OS. The others are using 4.2.12, extensions and guest additions installed.

Can you provide a screen shot of this phantom window? I have never seen one and I work on Ubuntu guests daily.
Also post the guests log file ( as an attachment )

Perryg wrote:Can you provide a screen shot of this phantom window? I have never seen one and I work on Ubuntu guests daily.
Also post the guests log file ( as an attachment )

"Phantom window" is possibly the wrong wording - it's only shown as an empty window thumbnail in the taskbar in addition to the VirtualBox Manager GUI and the actual VM window. I also work with Ubuntu guests daily (two of the hosts in my post are long-term hosts that have been running ubuntu VMs since roughly 10.10 or so) and have never seen this. I'll have to recreate the guest - since it was new and reconfiguration isn't that difficult, I deleted it and intend to recreate it to see if this was a fluke. If the thumbnail shows up again, I'll post a screenshot. Worst case, I guess I'll disable 3D acceleration and run in fallback mode - that's the only way to get the VB mini bar to work reliably when in fullscreen in my experience.

I suspect your phantom what-ever is a gpu indicator which was added to the VBox taskbar showing that 3D is enabled and working. ( I don't use the VBox taskbar so I don't know when this was introduced but may not have been with the older GAs you are using ) If you can reproduce this and post a screen shot I will investigate for you.

As far as fallback that would not be a good idea with 13.04. Canonical did away with true fallback mode and instead started using gallium software rendering which is very CPU intensive. ( as much as 30% to 40% overhead continuous )

As for the mini toolbar placement can cause the issue if you try it at the top it may work better, or use the host+home key instead of fallback is preferred.

Perryg wrote:I suspect your phantom what-ever is a gpu indicator which was added to the VBox taskbar showing that 3D is enabled and working. ( I don't use the VBox taskbar so I don't know when this was introduced but may not have been with the older GAs you are using ) If you can reproduce this and post a screen shot I will investigate for you.

As far as fallback that would not be a good idea with 13.04. Canonical did away with true fallback mode and instead started using gallium software rendering which is very CPU intensive. ( as much as 30% to 40% overhead continuous )

As for the mini toolbar placement can cause the issue if you try it at the top it may work better, or use the host+home key instead of fallback is preferred.

Sorry, I was referring to the Windows taskbar, not the VBox taskbar - it's showing up there like an open window, but there's no actual visible "window" on the desktop that corresponds to it. I'll try to get a screenshot.

Running the "Gnome Fallback (no effects)" session is pretty performant for me, and doesn't actually require 3D acceleration to be on for any of the hosts I use it on. It's certainly not applicable for everyone, but it works in my case pretty well. Failing that, I can always install the Mate desktop.

Here is a screenshot showing the window thumbnail I'm talking about. You may have to click the image to see it fully - the important bit is at the bottom.

I now see what you are talking about. I have to say I don't run/have windows host any more. I do have a few Windows guests that I nest another VBox in to test but none with Win8 since I totally loath the design and decided to stick to 7. I would actually post this question to the DEVs at bugtracker. Be sure to post the guests log file and the screen shot.