I'm a developer by trade but I've been asked to maintain our Ubuntu servers and am in need of some general advice as I don't really have any experience in this area...
apt-get upgradeonly update Ubuntu with minor incremental patches (e.g. if you start on 12.04 LTS you will always stay on 12.04 LTS) or does it also do major release upgrades as well?
We are running a standard LAMP server but it is for a product that is used 24 hours a day so it is important we minimise downtime. Will doing the standard aptitude upgrades cause downtime for the users? Will the server need restarting afterwards? Does it restart automatically? etc
Ideally we would like to run the minor updates without testing, so do the patches ever contain things that might break compatibility with something or are they purely just bug fixes and security enhancements?
If anyone has any nifty tips/tricks as well it'd be great to hear.