Paolo,
A few top-level mappings might be sufficient. http://openjena.org/ is currently giving me 403, so I did the possible (via links from somewhere else).
The EBS on openjena isn't attached and rebooting does not bring it back. It should be mounted at /media/ebs but it's gone.
Could you, as a Talis person, see what the AWS console says and reassign the EBS to the machine? Merely being root on the box isn't enough.
Thanks Andy