I had installed VirtualBox a while ago on my laptop running my Slackware64 test environment, so I could experiment with the program a bit. Then I forgot all about it.
Today, I upgraded to the latest set of slackware64-current packages, including the new 18.104.22.168 kernel and when I rebooted to that new kernel, I saw an error message scrolling by stating that “the vboxdrv kernel modules failed to load”. Of course… a new kernel needs all external modules to be recompiled.
When installing VirtualBox, I had already noticed that the installer is Slackware friendly; it installed a nice “/etc/rc.d/rc.vboxdrv” boot script and updated the “rc.local” script so that it runs “rc.vboxdrv” on boot. Well done!
It is easy to rebuild the missing VirtualBox kernel modules using that rc script: you just need to run it once with the “setup” parameter.
root@alienteepee:~# /etc/rc.d/rc.vboxdrv setup
Stopping VirtualBox kernel module ...done.
Recompiling VirtualBox kernel module ...done.
Starting VirtualBox kernel module ...done.
That’s all there is to it!