Redmine: want to run webrick service as background process

I am completely done with my redmine installation in ubuntu server. I am testing the server using the following command:

ruby script/server webrick -e production

But when I press ctrl+z it stops. So I want to start this one as a service or process in Ubuntu.

I tried this with this one:

ruby script/server webrick -e production -du 

It shows the process is running but in the browser no page is shown.

Do you have any suggestion how I can resolved the problem??

The following command works well on my system :

./script/server webrick -e development -d

The server is not stopped when I close my shell.