I have a headless server running Ubuntu 17.04 Server that is normally controlled by SSH from a Mac. The nags to upgrade to 17.10 led me to a "not recommended to perform a upgrade over ssh" dialog.
So to accomplish the upgrade directly, I hooked up a monitor and keyboard and found nothing would display. Reboots produce a brief "Ubuntu 17.04" at screen middle thereafter nothing but a blinking cursor in the upper left corner. But the SSH connection continues to work as it did before.
What do I need to do or what is missing to control the server directly using keyboard and display?
Next I created a bootable flash drive containing a Ubuntu 17.10.1 Server thinking that would be another way to install an upgrade.
The flash drive boots and prompts display normally on the monitor. The installation process for the hardware did not seem to have an option to upgrade an existing installation (17.04 in my case). I got very nervous about what settings and previous package installations might be destroyed, so the process was aborted.
Is this booting from a flash drive a reasonable way to upgrade?
Thanks for answers and any suggestions.