UTM serial device in case no display on boot

August 27, 2024

For VM server images in particular, the main display of the VM may never activate. The UTM message is like:

display output is not active

This is solved by powering off the VM, and adding a Serial Device under the UTM VM settings. Rebooting will automatically popup a separate windows for the Serial terminal, where boot messages and login can be accomplished. Often the main display window will then start working.