Learn ICT

I'm far from the first to say this, but since I ran across it yesterday I'll repeat it - a backup isn't a backup until it has been successfully restored.  The more important the content, the more important the backup strategy.  In Joomla you might use something like Akeeba (used to be called JoomlaPack) and/or you might rely on backups performed by your hosting provider.  As long as you have thought through the process of how often to back up, and how many backups you need to keep, this should be fine - as long as you know for sure that you can successfully restore the backup when and if the time comes that you need it.  This means you must test it.

As far as the backup strategy goes, some might think that they will backup every day, but they'll only keep one backup to save space.  This strategy is fraught with danger as if something happens (eg you get hacked) and it is not noticed or reported for two days, your most recent backup is now hacked also.  So you need to keep as many backups as will allow you to go back to a 'good copy' when necessary.

Remember also that some kinds of backups allow you to restore individual files, while others are whole site 'all or nothing' backups.  So you might have to undo a lot of work to fix a problem - sometimes you just have to say no, we'll just re-do the part that is broken, we can't (for example) restore the whole site to a point two weeks ago.

Moodle is an example of a program where backups are critical - if you're going to allow and encourage teachers and students to store so much of their work online,  it's hugely important that if anything goes wrong it can be recovered.  Moodle allows for automated course backups - these are important so that you can restore just one course, or part thereof, if necessary.  Also you should have a whole site backup strategy.  This will need to include, as a minimum, a database backup and a backup of the moodledata folder (this is normally the name of the folder where uploaded files are stored).  If you have added any third party plugins or done any customisations, you will also need to backup the whole moodle folder. This process is well documented at Moodle.org (http://docs.moodle.org/20/en/Backup) - there is also a page for Moodle 1.9 site backups at http://docs.moodle.org/19/en/Site_backup.

Best wishes with your backup strategy - it really is important and can save you from a catastrophe of losing a lot of very important work from a lot of people!