How to restore SharePoint from SQL backups?

I have been tasked with restoring our SharePoint instance for our Disaster Recovery Procedure. We store our backups of SharePoint onto tape via Netvault, we use the SQL plugin and also backup the entire system. So my understanding so far is that I need to backup the unattached content database then import it again into SharePoint. http://ift.tt/1zMsF0h Unfortunately when attempting backup the unattached database I receive this error 'SharePoint object [SPContentDatabase Name=restored_content] is in an unsupported state, and could not be used by the current farm. '. Any help with getting round this would be great. Also if there is an easier method of restoring SharePoint from the data I have I would be more than welcome to hear it!