Install VirtualBox Guest Additions on Fedora 26
NOTE: If your user does not have root rights, add it to the root group (probably ‘wheel’).
$ dnf update kernel* $ sudo reboot
After it boots up again, the guest additions should be up and running, and you should be able to see your desktop on full screen.
Install VirtualBox Guest Additions on Debian Stretch (9)
Insert the VBoxGuestAdditions CD image from the ‘Devices’ menu. (I had a lot of mount issues with this). It should automatically mount and automatically run.
If it does not autorun, you have to manually run the VBoxLinuxAdditions.run script. First solve any root permissions you may have (adding $USER to the visudo file should solve it: insert a line right after ‘root’ with your user name). Then go to
/media/cdrom0 or wherever your VBoxGuestAddition.iso is mounted and issue:
# bash VBoxLinuxAdditions.run
It should run seamlessly if everything is OK.
You are welcome to share your comments.