virtualbox.org

host: mac OS X
guest: kubuntu 64bit

after starting kubuntu on virtualbox I get black screen on my kubuntu. If I waite a while, I get the login window from kubuntu, but after entering the password I get black again. So I think kubuntu is running, but I get this black screen, like a kind of screen saver. Maybe it a problem with a the display options or a kind of automatic screensaver?

I got this before, my solution was to mounted a new clean version of kubuntu. Now I saved some important data on the kubuntu, that I dont want to lose again.

I was looking for solutions on the net, but nothing fits my problem. I would be thankful for any help!

my account name under kubuntu is: simulant
[img]start.jpeg[/img]
[img]blackscreen.jpeg[/img]
[img]screen.jpeg[/img]

I rather doubt that your host OS is relevant here. Moving this topic to "Linux Guests".

Please post a VM log file. With the VM fully shut down, right click and "Show Log" in the GUI, save "VBox.log" (ONLY) to a zip, and attach the zip here.

mpack wrote:I rather doubt that your host OS is relevant here. Moving this topic to "Linux Guests".

Please post a VM log file. With the VM fully shut down, right click and "Show Log" in the GUI, save "VBox.log" (ONLY) to a zip, and attach the zip here.

thanks mpack, here ist the log File:

VBox.log wrote: 00:00:01.140902 Host RAM: 8192MB total, 5320MB available
...
00:00:01.217792 RamSize <integer> = 0x0000000187800000 (6 568 280 064, 6 GB)
00:00:01.218304 VRamSize <integer> = 0x0000000005f00000 (99 614 720, 95 MB)

RAM overcommitted. Reduce to 2GB.

VBox.log wrote: 00:00:01.217788 NumCPUs <integer> = 0x0000000000000005 (5)
...
00:00:01.446348 CPUM: Logical host processors: 4 present, 4 max, 4 online, online mask: 000000000000000f
00:00:01.446354 CPUM: Physical host cores: 2

How on earth do you expect to assign 5 cores to a VM when the host only has two to begin with, and the host OS needs at least one for itself? Reduce to 1.

I also suggest that you upgrade to 5.0.12. You should always install bugfix releases.

Along with the problems mpack already mentioned, Kubuntu with Plasma 5 needs 3D acceleration disabled. At least on OSX hosts.

loukingjr wrote:Along with the problems mpack already mentioned, Kubuntu with Plasma 5 needs 3D acceleration disabled. At least on OSX hosts.

3D acceleration is disabled

opeNewbie wrote:How on earth do you expect to assign 5 cores to a VM when the host only has two to begin with, and the host OS needs at least one for itself? Reduce to 1.

it was working fine before, I reduced it now to your proposal. I have the latest version of vbox installed. Black screen problem remains.
new log file:

Try VB 5.0.12

loukingjr wrote:Try VB 5.0.12

okay, my version of VB is 5.0.10. The automatic update doesnt show any new updates. I will make an manual update.

just looked at your log. The only evidence I see of guest additions is… You need to update them.

loukingjr wrote:just looked at your log. The only evidence I see of guest additions is…

Code: Select all

00:00:16.130131 VMMDev: Guest Log: 00:00:00.001223 main     Executable: /opt/VBoxGuestAdditions-4.3.28/sbin/VBoxService

You need to update them.

I installed now the 5.0.12 version of VBox. Black Screen issue remains. New Log file:

see my last post.

loukingjr wrote:see my last post.

dont really understand what and how should I update now, sorry... can you plis describe it?

You keep saying "new log" and then posting the same log as before: still 6GB RAM and 5 vCPUs, 5.0.10.

sorry , last update was somehow a mistake

Ok, the only remaining issues I see in the log is (a) you don't have an extension pack installed on the host - so any VM that tries to use USB will fail, and (b) you are using obsolete Guest Additions from the Ubuntu fork of VirtualBox - you need to install current and official GAs.

Beyond that, the VM seems to be working: the GAs announce themselves in the log, which means that the guest OS successfully booted, even if you couldn't see anything. Another issue to consider is whether your OpenGL host drivers are working - an OpenGL test app should be useful to answer that.

One last thing: I recommend that you stop using "Suspend" until you have a working state. Reboot your VM from new each time.