15

Inside a VirtualBox VM, I have installed myself an Ubuntu 16.04.1 LTS Server installation. However, when I installed the ubuntu-desktop package and rebooted, this happened:

Exact command I used: sudo apt-get update; sudo apt-get install ubuntu-desktop
..and then a reboot command.

This just seems like a corrupted top-left portion of the screen, as my cursor can appear in view (but corrupted):

This is a purely graphical issue because I can use the keyboard to successfully progress to a desktop:

Note: On startup it shows correct graphics for a split-second then reverts to glitch.

Any help on this?

  • Note that the screen is perfectly fine for a split second after the machine starts everything. Then the resolution messes up and the graphics die. – Dev Jan 5 '17 at 14:02
  • The pattern of visual defects in your screenshots is similar defects that are caused by a bad stick of RAM memory in a physical machine. As a troubleshooting device please try to add more RAM to the virtual machine and check if the problem goes away. – karel Jan 5 '17 at 14:08
  • I gave it 128 MB of graphics memory and 12 GB of RAM - for a split second it did show the login screen like before (snagged a screenshot here) but after that, this happened again – Dev Jan 5 '17 at 14:12
  • Possibly. Maybe this is why Google Chrome has been killing random tabs. Let me try giving it less RAM then. – Dev Jan 5 '17 at 14:14
  • Same result. Proper screen for a split-second and then this. – Dev Jan 5 '17 at 14:15
20

I have also experienced this problem before and it is easy to work around:

Press CtrlAltF3 to switch to text terminal and then CtrlAltF7 to switch back to GUI (alternatively CtrlAltF1 in the case of some newer Ubuntu versions – simply try it if CtrlAltF7 does not work).

If your host is Linux, too, the mentioned keystrokes will influence the host machine. Use the Host key instead of CtrlAlt to influence the guest.

References:

  • 1
    I had the same problem with Linux Mint and this works for that too. – Mark Dec 20 '17 at 23:26
  • With an Ubuntu 18.04 or 18.10 Guest, you need to use <CTRL>-<HOST-KEY>-<F2> followed by <CTRL>-<HOST-KEY>-<F1>. – PJ Singh Oct 8 '18 at 23:37
4

This may be obvious to some, but in my instance (Ubuntu Host), Ctrl+Alt+F1 switched the entire host video mode, and switching back didn't change the status of the guest video. The trick was to use HOST+F1 (e.g. the RIGHT Ctrl key, no ALT), and then HOST+F7 to switch back.

2

Hit this scrambled/distorted screen today with 18.04 installer. I fixed it by increasing the video memory of the VM.

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