I'm in the process of putting a second disk image on a NAS from my new Mac until I realised I'd ran out of space. Thing is, the Superduper images and Acronis snapshots from my PC's are all I keep on this particular NAS so I was a bit confused. I eventually tracked it down to an enormous diskimage of my Superduper MBP backup which has been going for a while on a weekly basis. Why does the diskimage balloon so much? Can I shrink it?