Shutdown in CentOS requires halt argument

To shutdown in Ubuntu, I issue as root shutdown -P now. However, in CentOS, the computer does not shutdown and I get the message

<pre class="src src-sh">Telling INIT to go to single user mode.

INIT: Going single use INIT: Sending processes the TERM signal INIT: Sending processes the KILL signal sh-3.1#

The shell is active. Using Google I found this which states I need the -h (halt) argument whenever I want to power down. Don’t know why this wasn’t required on Ubuntu. To summarize, issue shutdown -P -h now in order to shutdown the computer.