I am a new Linux admin, and I have inherited a few machines that have been running for quite awhile without being updated. The login screen says there is 275 updates available with 150 of them security updates. I've done quite a bit of research on the apt-get command, and I don't think I'll have any problem running the updates, but I of course fear that with so many updates to be done something will not match up just right, and things will break. I've considered doing only security updates, but the number of updates is still very high. Since this is a virtual server I plan to clone it, and then run the updates on the clone first as a test run, and as long as everything goes ok then move on to the test server, and finally the production server.

Besides getting a good back up, and making another clone for a quick rollback what are some other things I should be thinking about? Are my fears well founded or do updates usually run smoothly, and not break too much? Should I update everything in one step or should I break it down and upgrade small groups of packages at a time? Any advice would be greatly appreciated.

-Jake

I've applied hundreds of updates at once on various Ubuntu installs and only had one failure, and that was an attempted upgrade to new distro.

Your plan is fine, make a backup, apply updates to the server and test.

It would take an inordinate amount of time to attempt to go through the updates and apply one but not another. If most are security, many of those are likely patches and then new fixes, which will be applied in the correct order if you accept all at once.

Can't go wrong with a complete backup, personally I make periodic backups of all of my OS using fsarchiver.

In a production environment that is the way to go with every update, not only if there are many updates at once. Good plan, just try it.