[ubuntu-za] Server upgrade question

[Wikus]

Afternoon all ,

I have a question regarding upgrading my Ubuntu server.

Scenario:

I have an Ubuntu 11.10 server. It was a fresh install. Server is not on 
internet.
Services used: Samba , apache , php , MySql , disk qoutas , webmin
Users: Just over 200

I want to know , a: Can I upgrade the server to 12.04 from cd like you 
can with desktop ? (boot with 12.04 server edition cd and upgrade)
b: If yes , what is my chances that all my configs and everything will 
still be working and in place after the upgrade ?
This is a live production system and I can't afford to loose my systems. 
I obviously will make a proper backup and I know there is always a danger.
I would just like to know how high or low chance there is of success 
from someone who already did it.

Thank you

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