Last update in the batch of 5. Ever made that mistake of deleting something you shouldn't...read on.
Phil Walton, (Joomla! volunteer, SoftForge) had a problem recently, where his apprentice, accidentally went too fast and deleted everything, something that could quite easily happen to anyone. The conversation we had moved towards how people tackle these sorts of issues.
Phil's team had disaster recovery plan in place to resolve the issues. Eoin Oliver, (Joomla! volunteer, Square Balloon) asked about Phil's disaster recovery set-up to see how other companies handled disaster recovery, as this is very important.
Brian Teeman, (Joomla! founder) has made some videos on Akeeba Backup which would be useful for anyone using that backup extension.
People asked about using Off site storage such as Amazon S3 in combination with Akeeba Backup (other off-site solutions are available). Brians videos cover this topic.
Phil asked whether Brian thought it would be worthwhile backing up just the database and not the files once a site was live.
Brian said that he is concerned not only with the backup, but also with the speed of recovery, which could be important in an emergency situation. Brian also pointed out that it could be a regulatory or contractual requirement for some websites such as government that the sites are up-and-running within a certain time limit.
IMPORTANT NOTE: It should also be noted that backing up the database only would not backup any files for new extensions that were added. Furthermore, if you are creating new content, you are almost certainly adding new images, these would also not be backed up.
With regards to the backup process, and automating offsite backups. Brian does daily backups. He sets them to be automatically deleted, except for on a certain day of the month. This is important because if your site gets infected you may not notice until a few weeks down the line. If you only had a weeks worth of daily backups that would be a flaw.
Brian pointed out that there is no point in doing the backups if you are storing them on the same server. If the server goes down you will lose all of the backups. It is not unfeasible to think that there could be a hardware failure such as a hard disk drive which would significantly reduce the possibility of you retrieving a backup stored on the server.
Phil made a good point that on occasion there could be a scenario where you accidentally delete all of your files. In that instance when you restore the site you do NOT need to restore your database because that part hasn't been deleted.
For good disaster recovery you should have domain on one server, site on another server, backups on another server, and emails on another server.