HTTP/1.1 400 None
Content-Type: application/xml
Content-Length: 121
Date: Mon, 28 Nov 2011 18:19:37 GMT

<badRequest code="400" xmlns="http://docs.openstack.org/database/api/v1.0">
    <message>
        Volume 'size' needs to be a positive integer value, -1.0 cannot be accepted.
    </message>
</badRequest>