I have got a Virtualbox with debian to build up windows machines using unattended. This virtual HD went up to 54Gb but internaly on 28Gb were used. So when I wanted to move out of that machine it took ages. I wonder if there is a easy way to clean up.
start with liveCD,
install zerofree ( apt-get install zerofree)
When finish shutdown the virtual machine and execute on the host system:
VBoxManage modifyhd vdi_file.vdi compact
HOWTO: Reduce the size of a dynamic VDI file in VirtualBox
update:Â SytemRescueCD have zerofree installed by default as for version 3.1.0
As a new strategic to move people out of windows, i am using virtualbox as a replacement for old applications that only works on windows. So I use an unattended method to install those vboxes.
A few weeks back I found a problem when enable extra funcions (add-ons) for an smooth use of the machine. and i was 100% that the problem was on virtualbox software, but I could not know how to present it for the development teams to have a look.
My surprise was today that someone using same software reported the problem a month ago and today the fix was release con the 3.0.8 version.
Love open source!