I simply wanted to change the location of the home directory, so I followed these instructions:
usermod -d /path_to_new_dir a_user
However, Ubuntu 12.04 responds:
usermod: user a_user is currently logged in
So I checked
sudo who, and
sudo lsof -u a_user, but see nothing from a_user.
Nonetheless, I still try to kill the user:
sudo skill -KILL -u a_user and
sudo pkill -u a_user, but no luck. Ubuntu still responds:
usermod: user a_user is currently logged in.
Any ideas on what to try next?