The default crontab editor is nano on some systems. This is a pain. You can change this by setting the EDITOR environment variable. In BASH:
srv-4 / # set | grep EDITOR EDITOR=/bin/nano srv-4 / # which vi /usr/bin/vi srv-4 / # export EDITOR=/usr/bin/vi srv-4 / # set | grep EDITOR EDITOR=/usr/bin/vi _=EDITOR srv-4 / #
To make the change stick, you can add it to the profile script appropriate for your shell. We put it in /etc/profile.