...
In this example the server is running 9.10 . The and at the time, the next long term support release is was 10.04.
If we were behind multiple releases, for example at 9.04, we would first upgrade to 9.10 and then 10.04 by repeating the upgrade instructions.
...
Finally stop as many services as possible especially those not managed by Ubuntu.
As a precaution we also stop even services managed by Ubuntu. Examples include web server deaemons (Apache, nginx, etc), database servers (PostgreSQL, MySQL, etc), and any other non-critical services.
Perform the Upgrade
It is preferable to upgrade from the console. Even in the case of cloud or virtual computing try to get to a console. Most cloud and virtual systems provide a back door console access via the web browser.
Perform the release upgrade,
...