Beginning with systemd-230, all user processes are killed when a user session is ended, even if nohup is used, or the process uses the <function>daemon()</function> or <function>setsid()</function> functions.This is a deliberate change from a historically permissive environment to a more restrictive one. The new behavior may cause issues if you depend on long running programs (e.g., <command>screen</command> or <command>tmux</command>) to remain active after ending your user session.There are three ways to enable lingering processes to remain after a user session is ended.