One common way to increase your Joomla security (primarily when web hosted) is to change your database prefix (from jos_ to something else. e.g. jot_). An extension that can be used to do this is called 'EasySQL'.

I have noticed that /jumpbox/application_portal/privileged_scripts/ubuntu/app.rb contains references to the super user with 'jos_', so if you change your database prefix, assumably you should also make 2 changes in the app.rb file to refelect this new database prefix.

I'm guessing that this could be a cause of restore failures. Feel free to add to this post if there are additional areas where the database prefix are referenced in the Jumpbox for backups / restores (I couldn't find anywhere else).