How To Upgrade Your Server From Ubuntu 14.04 To Ubuntu 15.04

This guide will explain how to upgrade your Ubuntu 14.04 server to 15.04. Note that 14.04 is an LTS release, and 15.04 is not an LTS release. By upgrading, you will loose the benefits of long-term support. If you would like to upgrade your server, follow the steps below.

Step 1: Create a backup

Before doing anything, create a backup. You can restore your server in case anything goes wrong. Currently, Vultr offers free snapshots that you can restore your server from with all servers. Go to My Vultr to create a snapshot.

Once the snapshot has been created and you can confirm it works, continue reading.

Step 2: Change setting

You will now need to change the Prompt setting in the /etc/update-manager/release-upgrades file. Open this file with your favorite text editor.

Change the value of the Prompt setting from lts to normal.

Step 3: Upgrading Ubuntu

After confirming you have a working snapshot, and you have changed the setting, you can now execute the command to update Ubuntu:

do-release-upgrade

If you receive an error, please update the package list with:

apt-get update

Then, upgrade packages with:

apt-get upgrade

Then, try again.

When asked if you want to start an additional SSH daemon, type “y”:

If you continue, an additional ssh daemon will be started at port 
'1022'. 
Do you want to continue? 

Continue [yN] 

Open the port in your firewall when asked. Press “enter” once you’ve done this.

You will now see the packages that are going to be upgraded and the changes that are going to be made. Note that the upgrading process can take several hours, and you can’t cancel the process once Ubuntu is upgrading. This will break your server. Press “y” when you’re ready to upgrade your server to Ubuntu 15.04.

After the upgrade has finished, you can confirm your server is running on the new version by executing:

lsb_release -r