Upgrading from 3.5.4 to 3.6.2

[Necrosaro420]

Ok, I have never upgraded before, and I am pretty worried about something bad screwing up and losing over a years worth of posts etc.

What happens if when I upgrade to 3.6.2 if nothing works? Would there be a way to revert back to 3.5.4?

[Lats]

I doubt very much that nothing will work

However, it's always a very good idea to do a full database backup using the shell before running an upgrade - as per the docs.

[Beller]

As always back up your database before upgrading anything.