I have an installation of OpenBSD-current running headlessly within VirtualBox 6.1.16 on a headless Ubuntu Linux (Focal) system. Whenever I reboot the virtual machine (issuing the
reboot command as root in the guest system), the virtual machine halts, i.e. it stops running.
This is a nuisance when running the OpenBSD
sysupgrade tool to upgrade to a new snapshot release, as it means having to log into the host system to restart the virtual machine twice (after the initial reboot, and then again the upgrade has completed and the system reboots again).
This is different from how the same identical virtual machine functions in VirtualBox 6.1.18 on macOS (using the GUI there). There, the virtual machine is kept running, allowing the system to properly reboot without having to interact with the VirtualBox GUI on the host system. It is also different from how another virtual machine running Kali Linux behaves on the same Ubuntu host system.
On Linux, I start this virtual machine,
mymachine, as an unprivileged user like so:
VBoxManage startvm --type headless mymachine
Should I start it in some particular way, or should I change the machine's configuration in some particular way (I haven't found anything that seems related to this in the machine's settings)?
The only substantial difference between the OpenBSD virtual machine on macOS (which reboots properly) and the same machine on the Ubuntu host (which halts instead of rebooting) is that the former uses a VDI disk image while the latter has a VMDK disk image.