You have Jenkins installed, there are a few things you may want to do to your environment to make life easier.

Login with Jenkins User

Be default the “jenkins” user is not allowed to login.  So even as root you can’t  “su – jenkins”.  If you need to be able to do this, then the following command will help you out:

sed -i -e 's/\/var\/lib\/jenkins:\/bin\/false/\/var\/lib\/jenkins:\/bin\/bash/g' /etc/passwd

Jenkins Auto-Start

In most cases you want Jenkins to start with the system is started.  Be default this isn’t the case, but it’s easy to change.

chkconfig jenkins on --level 2345

Manually Start/Stop/Restart Jenkins

Your probably going to need to manually start, stop or restart Jenkins at some point.  Here are the command lines:

service jenkins start
service jenkins stop
service jenkins restart