Terminal output scrolling is gone (Headless 11.10 Server, Upgraded from 10.10)

The behaviour you describe sounds like your terminal was stuck in the full screen "cursor addressing" mode used by tools like less and vi.

The mode can become stuck if those programs do not exit cleanly. For instance, if you kill -9 them, or are running them through an ssh session that disconnects. You can exit this terminal mode by running the following command:

tput rmcup

Or just try browsing a file with less and quit as normal. You should then have access to your scrollback and the contents of the screen when cursor addressing mode was entered.

If tput rmcup does not work, try

tput reset

instead.

Just reset alone worked for me.