Ubuntu guest: Seamless mode unavailable after guest additions installed.

Discussions related to using VirtualBox on Windows hosts.
Post Reply
bobdobbs
Posts: 25
Joined: 16. May 2008, 08:38

Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by bobdobbs »

I'm running Ubuntu 22.04 as a guest on a windows 11 host.

I've installed guest additions.

After installing guest addition, I try to start seamless mode or auto-adjust Guest Display.
Both of these options are greyed out.

I've rebooted the VM a few times, removed and re-added GA. But the options are still unavailable.

What's going on? How do I get the options working?
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by scottgus1 »

bobdobbs wrote:Ubuntu 22.04 as a guest
...
After installing guest addition, I try to start seamless mode or auto-adjust Guest Display.
Both of these options are greyed out.
This will likely mean that the Guest Additions install failed, or the GAs are failing to fully start. This may be because of the pre-installed GAs Ubuntu "helpfully" puts in their OS's.

Uninstall GAs from the VM, reboot. Check if there are any left-over GAs files in the Ubuntu OS (web-search how to do this). Then run the GAs prerequisites, which are same as for Virtualbox on a Linux host https://www.virtualbox.org/manual/ch04. ... ions-linux and https://www.virtualbox.org/manual/ch02. ... nux-prereq. Then load the GAs ISO using the VM window's Devices menu "Insert Guest Additions CD Image" command. Then install the GAs from the VM's CD drive.
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by fth0 »

scottgus1 wrote:This will likely mean that the Guest Additions install failed, or the GAs are failing to fully start. This may be because of the pre-installed GAs Ubuntu "helpfully" puts in their OS's.

Uninstall GAs from the VM, reboot. Check if there are any left-over GAs files in the Ubuntu OS (web-search how to do this).
I disagree with the stroke-through parts for the following reasons:

Many Linux distributions (Ubuntu included) pre-install older versions of the VirtualBox Guest Additions kernel modules, but they're usually part of a Linux distribution package with a lot of different kernel modules. Uninstalling this package as a whole is a very bad idea (TM). Renaming only the pre-installed VirtualBox Guest Additions kernel modules is feasible, but messes with the root installation.

The installation of the Oracle VirtualBox Guest Additions either succeeds with building its newer kernel modules and overriding the pre-installed kernel modules or not, and I don't see any disadvantage in having the pre-installed kernel modules in the latter case. Am I missing something?
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by scottgus1 »

fth0 wrote:Am I missing something?
Highly likely not :lol: My suggestion was really a guess, based on a post or two that I remember:

That there was a mix of versions of either Virtualbox or Guest Additions reported in a log from a Linux host, and the diagnosis was that the version of VB or GAs provided by the Linux distro hadn't been fully removed by the new version installed, which could cause poor or failed operation of VB or GAs.

However, from your post, it sounds like the new GAs won't clear away the old GAs at all unless the new install completes. Maybe what I saw above was only for Virtualbox on the host?

'Twas only a stab in the dark, and I'd be glad of further info!
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by fth0 »

scottgus1 wrote:'Twas only a stab in the dark, and I'd be glad of further info!
Your general advice is good, of course: To install the VirtualBox Guest Additions and make sure that the installation was successful. Only the part regarding uninstalling the GA from Linux distributions is often wrong, and IMHO this comes from a misunderstanding supported by a log message in the VBox.log file. Let's look at a common example:
VBox.log file of a Linux guest wrote:
00:00:22.547356 VMMDev: Guest Additions information report: Version 6.0.0 r127566 '6.0.0'
[...]
00:00:25.988471 VMMDev: Guest Log: 09:33:54.515170 main     VBoxService 6.1.26 r145957 (verbosity: 0) linux.amd64 (Jul 28 2021 18:25:57) release log
The VirtualBox Guest Additions (GA) consist of kernel modules (e.g. vboxguest.ko, vboxsf.ko) and applications (e.g. VBoxService). Some Linux distributions (e.g. Ubuntu) pre-install an old version of the GA kernel modules (e.g. 6.0.0) as part of a package containing hundreds of kernel modules, but they do not pre-install a GA package containing the GA applications. Although the first log message above is called "Guest Additions information report", it only indicates the version of the vboxguest.ko kernel module. In consequence, it is debatable if you can call this "GA pre-installed by the Linux distribution".

If the VirtualBox GA kernel modules cannot be built during the installation of the VirtualBox GA 6.1.26, you'll end up with the combination of the pre-installed kernel modules and the newly installed GA applications, as indicated by the combination of both log messages above.

If the VirtualBox GA kernel modules are successfully built during the installation of the VirtualBox GA 6.1.26, they will be installed in addition to the pre-installed kernel modules and they'll take precedence.

All in all, there is no good reason to uninstall the pre-installed kernel modules, especially since it is difficult to do that.
bobdobbs
Posts: 25
Joined: 16. May 2008, 08:38

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by bobdobbs »

[quote]Your general advice is good, of course: To install the VirtualBox Guest Additions and make sure that the installation was successful[/quote]

What's a measure for the success of the installation other than the issues that I'm getting?

At the moment it appears that the installation isn't successful, even after repeated uninstallations, reboots and reinstallations.
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Ubuntu guest: Seamless mode unavailable after guest additions installed.

Post by fth0 »

bobdobbs wrote:What's a measure for the success of the installation
VBox.log file of a Linux guest wrote:
VMMDev: Guest Additions information report: Version 6.0.0 r127566 '6.0.0'
  vs.
VMMDev: Guest Additions information report: Version 6.1.34 r150636 '6.1.34'
Search the VBox.log file for this "Guest Additions information report" log message. If it does not report the GA version that you installed (like in the example above), something went wrong, and 80% of the time the user didn't follow the instructions in the VirtualBox User Manual and/or ignored error messages in the terminal window displayed during the installation.

If the log message reports the correct version, please provide a (zipped) VBox.log file from a complete VM run, so that we can try to provide further guidance.
Post Reply