modprobe vboxguest failed ubuntu 20.04

Please provide details:
Which operating system (and version) is your host system?
Which operating system (and version) is your guest system?
Which packages and which version of the virtualbox software (and from which source) do you have installed, and on which of these two?

And for the availability of virtualbox on Ubuntu 20.04:
What would you think if you install Ubuntu 20.04 as (planned) host system, end then find out that virtualbox does not exist for that plattform? In my opinion it is necessary that Ubuntu provide a version for Ubuntu 20.04 even if virtualbox.org does not yet have a dedicated version of their own.

I have already added the information you requested.

Please add as a comment:

Is Ubuntu 20.04 your host system?
Which system(s) do you want to install as guest systems in virtual machines?

Why do you want to activate the guest additions on the host? This does not make sense.

All the information you request is already described. I repeat it again step by step.
1. A Dell inspiron 3000 series laptop was installed with Ubuntu 20.04 LTS
2. Then, the described commands were executed (apt install virtualbox virtualbox-ext-pack).
3. All those errors came out after installation.
I don't know which part of these steps doesn't make sense to you. The only thing that does not make sense to me is that Ubuntu has a virtualbox package in the Focal Fossa repositories, which does not yet have an official version of Oracle for this distro.

I still do not see any information about the guest systems that you want to install.

What is the output of the commands

uname -a
lsb_release -crid
dpkg -l | grep virtualbox

If you doubt the validity of the virtualbox packages in the repositories for Ubuntu 20.04, why are you then installing them?

no guess systems yet. but if you want tell me what vm should i create and with what operating system

in Host dell laptop:

uname -a
Linux mrv 5.4.0-29-generic #33-Ubuntu SMP Wed Apr 29 14:32:27 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -crid
Distributor ID: Ubuntu
Description: Ubuntu 20.04 LTS
Release: 20.04
Codename: focal

dpkg -l | grep virtualbox
ii virtualbox 6.1.6-dfsg-1 amd64 x86 virtualization solution - base binaries
ii virtualbox-dkms 6.1.6-dfsg-1 amd64 x86 virtualization solution - kernel module sources for dkms
ii virtualbox-ext-pack 6.1.6-1 all extra capabilities for VirtualBox, downloader.
ii virtualbox-qt 6.1.6-dfsg-1 amd64 x86 virtualization solution - Qt based user interface

Which output do you receive (on the Dell host) for the commands

lsmod | grep vbox
vboxmanage --version
sudo modprobe -v vboxdrv
dmesg | tail

lsmod | grep vbox
vboxnetadp 28672 0
vboxnetflt 28672 0
vboxdrv 487424 2 vboxnetadp,vboxnetflt

vboxmanage --version
6.1.6_Ubuntur137129

sudo modprobe -v vboxdrv
nothing out

dmesg | tail
[ 13.609024] vboxdrv: Found 4 processor cores
[ 13.643440] vboxdrv: TSC mode is Invariant, tentative frequency 2400007434 Hz
[ 13.643442] vboxdrv: Successfully loaded version 6.1.6_Ubuntu (interface 0x002d0001)
[ 13.657151] VBoxNetFlt: Successfully started.
[ 13.670341] VBoxNetAdp: Successfully started.

This looks correct.

And all messages about vboxguest or VboxClient are irrelevant. These should be running only inside the guest systems.

I just created a windows 10 VM for testing. And virtualbox doesn't work well. The guest window is static attached to the screen and cannot be moved (I already installed guest additions)

Your explanation does not solve the problem.

PS: Virtualbox should be removed from the Ubuntu Focal repositories until there is a version suitable for this distro

"PS: Virtualbox should be removed from the Ubuntu Focal repositories until there is a version suitable for this distro"

Why? I definitely prefer having a version from Ubuntu than no version at all.

"provisionally" until a version for Focal Fossa comes out. According to Oracle, Version 6.1.6 is only for Ubuntu 14.04 / 14.10 / 15.04 / 16.04 / 18.04 / 18.10 / 19.04. Not 20.04 http://download.virtualbox.org/virtualbox/debian/dists/

And the problem with resizing the guest window may be caused by https://www.virtualbox.org/ticket/19496

you are giving me the reason. The solution to this problem is in the next version 6.1.7 (not available) and will fix the problem for 19.10 (not for 20.04). So it is better to remove virtualbox from Ubuntu Focal repositories

we have different points of view. You prefer that a version of virtualbox incompatible with this distro remain in the Ubuntu Focal repositories. I prefer to withdraw it until oracle publishes a compatible version
This is not new. Ubuntu has removed many incompatible programs from the Focal repositories.
The point is that your position can generate instability in the system. And this should not happen with an LTS version.

Where do you see an incompatibility? As far as I can see it works.

https://www.virtualbox.org/ticket/19496 is a problem affecting not only Ubuntu 20.04 but also other operating systems and versions.

I suggest that you complain at virtualbox that they have not yet updated their repositories with a version that is marked as dedicated for Ubuntu focal.

If the problem was with the Oracle repository then I would go to Oracle, but since the problem is in an Ubuntu repository then I am in the right place.
What happens is that you are trying to close this thread in the John Wayne way

What is now the issue?

The title of the question is "modprobe vboxguest failed ubuntu 20.04"
I tried to explain that the vboxguest kernel module makes sense only on an Ubuntu (or other Linux) system that is running in a guest virtual machine.

All other discussion should have gone into a separate question.

You complain that Ubuntu provides packages with virtualbox software for Ubuntu 20.04. I do not see a problem with that. Oracle does not provide a package that is marked as "works with Ubuntu 20.04", but the Virtualbox 6.1.6 version packaged by Debian (not Ubuntu) works well on Ubuntu 20.04, and I assume that it even works on Ubuntu 20.10 (the development version).

Is there somewhere a statement by Oracle telling that "Virtualbox does not work with Ubuntu 20.04"? No, it is just the case that Oracle has not (yet) made a version that is flagged as "definitely works with Ubuntu 20.04". Ubuntu has proven that the package created by Debian works well on Ubuntu 20.04.

As long as you cannot provide any example on an incompatibility between the Ubuntu-provided virtualbox packages and Ubuntu 20.04 (which is not a general problem of the 6.1.6. version on several operating systems), I do not see any reason for removing these packages from the Ubuntu repositories.

In my opinion, no package an LTS version should have these problems, like the one I describe in my question and this problem should not exist. However for you it is irrelevant. So I suggest that you do not participate, and allow others to do so.

"no package an LTS version should have these problems"

Which problems?

I respectfully ask you not to ask any more questions, because I will not answer them. All the information is already published. Allow others to participate. Thank you

solved in vbox 6.18. Ubuntu need to update repo

My comments:

1. The number of the new version is 6.1.8 (not 6.18)
2. If you look at http://download.virtualbox.org/virtualbox/debian/pool/contrib/v/virtualbox-6.1/ and http://download.virtualbox.org/virtualbox/debian/dists/focal/contrib/binary-amd64/Packages you will see that Oracle provides a package for Ubuntu focal which is identical to the package for eoan (and even tells so in its name). This perfectly fits to my statement that the 6.1.6 version for eoan was well working also on Ubuntu focal.
3. Ubuntu is no rolling release, so the version of Virtualbox currently provided in the Ubuntu repositories for focal will not be upgraded any more (except in case that there are severe bugs detected).
4. There is an Ubuntu development version (20.10, groovy) which currently contains an adapted version of virtualbox 6.1.8, even if Oracle did not make any statement about Ubuntu 20.10 yet.

1. It is 6.1.8. A typographical error that I could not correct. You don't have to go to those unnecessary extremes.
2. If version 6.1.6 had no problems, as you affirm, then I would never have had to open that "issue" (you contradict yourself, since you were the one who provided the link where all the problems of this version 6.1.6 appear)

In summary, the problem has already been solved in 6.1.8. If ubuntu wants to update or not, for me it is already irrelevant. I have switched to the Oracle repository. This topic is closed and I will not reply to other comments