Reduce vdi disk size?

[gianinetto]

Hi,

I have setup a VM using virtualbox 4.0.4 with a standard vdi disk of 20GB (fixed size). Host OS is Windows 7 x64 and guest OS is Windows 7 x86.
Now I need to reduce the disk size as much as possible without changing its volume serial number (as reported by the DOS dir command). Is there any simple and fast way (I have to perform this operation on several VMs!)? Maybe using CloneVDI?

Thank you.
Marco

[mpack]

CloneVDI will compact it (assuming you turn that option on - recommended) and will quickly convert it to dynamic VDI format. Both steps together will reduce to a minimum the disk space it occupies on the host. Of course CloneVDI makes a clone, so you won't actually recover any space until you delete the original - which I suggest you only do after testing the clone!

[gianinetto]

Thank you.
I was not sure about the conversion from fixed to dynamic VDI. I will try as you suggested.