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
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").