According to http://www.oracle.com/technetwork/middleware/soasuite/learnmore/vmsoa-172279.html this is a Virtualbox disk image and your question is about resizing a Virtualbox disk image, which is probably better placed in the VM forum e.g.
Virtual Desktop Infrastructure and SunRay Clients
To my knowledge there is no easy command to simply resize a disk image using the VirtualBox Virtual Disk Manager and you will have to either add another disk and play with Linux LVM, or clone the existing disk image to a larger disk image. i.e. VBoxManage clonehd --existing oldhd.vdi newhd.vdi
Both steps are not easy to explain. I suggest to check the VirtualBox documentation at http://www.virtualbox.org/manual/UserManual.html or search the internet for information about how to resize a vdi disk image.
