[Users] Copy disks?

Hi All, When in the top tab Disks and a disk is selected I can do Add, Remove, Move but Copy is always greyed out, no matter what I try. Doesn't matter if the disk is thin provisioned or not, whether it is attached to a VM or not, whether the VM is running or not. How does one copy a disk? Or when is that button active? Regards, Joop -- irc: jvandewege