I have a Windows 7 VirtualBox virtual machine. The disk image file is 30GB and is one large .vdi file. If I change anything inside that (even a few KBs), Time Machine wants to backup the entire 30GB file each time. Actually even if I just boot up the virtual machine, Windows makes some registry changes etc and even with 0 user/application level changes it triggers the full 30GB copy.
Is there a way to make a virtual disk image such that it's Time Machine friendly? So if a few KBs/MBs are changed, only those sectors are copied over?