Packages upgrade

Standard way of keeping packages up to date is to connect via ssh or vnc, and type:

apt-get update
apt-get dist-upgrade

And optionally reboot when eg. linux kernel has been changed.

The only thing to remember is not to install grub when ask:

On next screen there will be question where to install grub:

Just don't choose any option.

If grub would install on /dev/xvda then it will rewrite beginning of partition and XEN will not boot the instance.

Upgrade process will warn:

but this is ok to continue.

Because grub thinks it's not installed anywhere, even after reboot there will be still old kernel in use. You can see kept back packeges:

root@test-ubuntu-v3:~# apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages have been kept back:
  linux-headers-generic-lts-quantal linux-image-generic-lts-quantal
0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded.

To resolve this conflict force install these packages and then reboot:

apt-get install linux-headers-generic-lts-quantal linux-image-generic-lts-quantal
reboot

After reboot new linux kernel should be used

Distribution upgrade

The whole procedure is to run from command line:

sed --in-place 's/precise/raring/g' /etc/apt/sources.list
apt-get update
apt-get dist-upgrade
reboot

This is the easiest way to upgrade from our Ubuntu 12.04 LTS image (named "precise") to currently the newest Ubuntu 13.04 (named "raring").