Today after upgrading Virtualbox on my Arch host I found that I could no longer run Virtualbox.
WARNING: The vboxdrv kernel module is not loaded. Either there is no module
available for the current kernel (4.4.3-1-ARCH) or it failed to
load. Please recompile the kernel module and install it by
sudo /sbin/rcvboxdrv setup
You will not be able to start VMs until this problem is fixed.
As told I could not boot any of my VMs.
It was not possilbe to run sudo /sbin/rcvboxdrv setup, all I got was another error message:
Loading modules: modprobe: FATAL: Module vboxnetadp not found in directory /lib/modules/4.4.3-1-ARCH
modprobe: FATAL: Module vboxnetflt not found in directory /lib/modules/4.4.3-1-ARCH
modprobe: FATAL: Module vboxpci not found in directory /lib/modules/4.4.3-1-ARCH
modprobe: FATAL: Module vboxdrv not found in directory /lib/modules/4.4.3-1-ARCH
After banging my head and reinstalling Virtualbox I found out that the problem is that virtualbox-host-modules package were simple removed. I suspect the dependency became broken when installing either the new arch kernel or the new Virtualbox package.
Simply reinstall the host modules again
# pacman -S virtualbox-host-modules
You will need to manually load the modules the first time:
# modprobe vboxdrv