Keep sessions alive across disconnects.
tmux
Start a named session and detach
tmux new -s build
# Ctrl-b, then d to detach
tmux ls
Reattach after a dropped connection
tmux attach -t build
Split without the mouse
Ctrl-b % vertical split
Ctrl-b " horizontal split
Ctrl-b arrow move between panes
Run something in every pane
tmux list-panes -F '#{pane_current_path}'
The detach prefix is Ctrl-b, not Ctrl-z. If a session looks frozen, press Ctrl-b then d before reaching for the keyboard shortcut.