Speaking from one paranoid organization to another, there are things you can do to back up what's there:
- Moodle 2.3.x still has course backups and can still include user data.
- Make sure you have a good backup of everything.
- Do both.
What we decided to do is basically back up everything every night. Our Moodle is hosted offsite on Debian/MySQL. Internally, we are a Windows shop, so we have dislike systems involved. Here are the steps we take:
- Schedule a nightly cron job to dump the Moodle database.
- Schedule a nightly rsync job on-site to sync the database, Moodle public html files, and Moodle data files. Since we use rsync (the cygwin version), only changes are synchronized making the time it takes nightly bearable.
- (Optional) Zip the database, html files and data together into a large archive snapshot.
- Back up what you've synchronized using whatever you normally do for internal backup.
This way, you should basically be able to restore everything to the way it was on any particular day for as far back as you keep your backup sets. You should periodically test this by restoring a complete backup to a test location (see Moodle Migration for details). We do this three times per year in between terms. It's work, but that's how you insure you CAN restore in the event of a real disaster.
This should work regardless of whether you run Moodle 1.9, 2.3 or 2.4.
As far as the upgrade issues, as with any CMS, plugins can always be the sticking point. About the only advice I have is to try to pick ones that seem to keep up.
