On: Su VS sudo su VS sudo -u -i

[lubutu]

I've just done some testing, and my sudo (1.7.4p6) does honour NOPASSWD in /etc/sudoers, when I sudo -su to any user. Are you sure your configuration is correct?

[johnkpaul → lubutu]

No, I'm not sure. I'm using Sudo version 1.7.4p5. sudo su <user> does not prompt for a password. sudo -su <user> and sudo -s -u <user> do prompt for a password.

[atombender → johnkpaul]

Works here. We use it extensively on our boxes to allow access to certain initscripts, among other things.