If never have a full backup on hand, the first priority is make a full backup immediately, 3GB of data is easy to handle, just stop the web server and UBB software, so that able to put the MySQL engine off-line, copy the whole database and web documents to off-line media, such as a high speed 8G USB fresh drive, it can be done in less than half hour, in case someone can access to the data center. Of course it would be better to have another copy in different media to avoid become a victim of Murphy's law. It better be done before replace the hard disk, as a new disk putting back into mirror stage, it put a lot of stress to the old hard disk.

The database and web document are most important things inside the hard disk, other thing can be rebuild, but not these information.