by Shawn LoPorto.
I went through the process of upgrading from 1.9.5 to 2.4.1 (that was the highest version at the time) and documented it for others on this post:
https://moodle.org/mod/forum/discuss.php?d=224561
I highly recommend that you don't use the backup as a process for upgrading. That feature is mainly for restoring a course to the same moodle version. The best way to backup your courses for upgrading is by doing MySQL dumps. This is also easier because it'll create this backup/dump (SQL file) for all your courses in one step (odds are all your courses are in one database). I describe the overall process in the post above - for the dump steps I refer to a WordPress post that I used and it describes the process quite well with pictures.
