Upgrade ubuntu server from jaunty to karmic

To upgrade ubuntu server jaunty(9.04) to karmic(9.10):

1. Update repository

$ sudo apt-get update

2. Upgrade current package

$ sudo apt-get upgrade

3. Install update-manager-core and do-release-upgrade

$ sudo apt-get install update-manager-core do-release-upgrade

4. Run do-release-upgrade

$ sudo do-release-upgrade

5. Follow the instructions, and wait until complete :)