For transparency, the process is quite painless, and takes about 30 mins per instance. We take a live snapshot before upgrading a module, then issue the following commands
apt-get update && apt-get upgrade -y apt-get dist-upgrade -y do-release-upgrade -d
to complete the upgrade. We also make a quick adjustment to your SSL Certificate settings before rebooting. That’s it! Some quick testing and then we move on to the next WordPress installation. The automatic security upgrades on your VPS takeover until we next need/want to upgrade your OS, which will be in approximately 2 years time on the release of Ubuntu 20.04.