I am looking for Web-Based tools to monitor Ubuntu Server ( disk space , ram , etc )
2 Answers
Look at Webmin Screenshots of Webmin
Debian package suitable for Debian, Ubuntu or other derived Linux http://prdownloads.sourceforge.net/webadmin/webmin_1.580_all.deb 14.8 MB
This is as complete as you can get
I would look at Munin which is available as package and generates historical graphs which can be useful when you thing things have changed.