virtualbox.org

Hello. I have a little issue with the Linux Guest Additions.

Steps to reproduce:
- install Debian 8 normally from the network ISO (WITHOUT GUI);
- login as root
- do the following command: - uncomment the line: - and modify it as follow: - add the following line just below: - save the file and quit the editor (CTRL + C --> :w --> CTRL + C --> :quit);
- do the following commands: - wait for the boot menu.
- observation: the parmeters that we modified above are good for the boot menu (resolution = 1024x768): - press <enter> to boot on GNU/Linux;
- wait for the login prompt;
- observation: the parmeters that we modified above are also good for the terminal (resolution = 1024x768): - login as root;
- insert the Guest Additions ISO;
- install the Guest Additions by the following commands: - wait for the boot menu;
- observation: the parmeters that we modified above are good for the boot menu (resolution = 1024x768): - press <enter> to boot on GNU/Linux;
- wait for the login prompt;
- observation: the parmeters that we modified above are NOT GOOD for the terminal (resolution = 800x600): Conclusion: Linux Guests Additions breaks the GFXPAYLOAD. (Title.)

Possible workaround: reject the screen resizing feature during installation. (I dont know how to do that.)

HOST:
OS: Windows 10.0.15063 (x64)
GPU: GTX 770

GUEST:
OS: Debian 8.8
Kernel: Linux 3.16.0-4-amd64

VM settings:
Default exept:
- RAM = 2048 Mo;
- VRAM = 64 Mo;
- CPU = 2.

Virtual Box:
Version: 5.1.22 r115126 (Qt5.6.2) + expansion pack.

Additional informations:
Installation packages: SSH server, standard system utilities.
The resolution switch happens during the initial system loading (just before the login prompt).

Thank's for help.

I am curious as to what benefit you think you are/would get from installing the guest additions in a CLI guest? AFAIK without X the guest additions can not impact the screen size and I know nothing in them that would impact the boot parm. Have you verified that during the update or distro package install the boot parm was retained?

I will say the last time I tested this in Debian I had to actually manually edit two different files to get it to work properly. I don't remember which at the moment but a search on google should find the information you need. I also think I had to blacklist something, but again that should turn up in a search. I do know that framebuffers are a part of the OS and not VirtualBox.

Finally be careful when tinkering with the GFX lines. They are for graphics and not framebuffers. Meaning that you might be able to get a full screen at boot and then a fall back at login.

Hello and thank's for your reply.

I use the Guest Additions because the shared folder feature which I need to use.

As you can see in the screenshots, the GFXPAYLOAD line works fine WITHOUT the Guests Additions.

It is after the Guest Additions installation that the problem happens.

And when I uninstall the Guest Additions by the command below, everything works again. So it's looks like that Guest Additions alters the boot (and "force" 800x600 console resolution).

Have a nice day.

Ok I found my notes on this. I set it like you in grub and it did as you saw, and remember I said something about a blacklist?.
Now add vboxvideo to "/etc/modprobe.d/fbdev-blacklist.conf" and reboot.

As a side note I don't remember this being needed is all distros but keep a note handy just in case.

SOLVED!

Thank's for the support and have a nice day.

You're welcome. I have since added this to the tutorial section Linux-guests because I have so many notes after all the years I find it takes too long to find anything these days.

Yup, you did well.