My inexperience in Linux makes me spent one day on this point: how to zeroing free space in order to call a compact on disk file.
— Solution 1 —
You can create a file big as all free space filled with zeros and delete it, wow, yeah! great idea! but I have a virtual dinamic disk bigger than real phisical space available.
So no way.
— Solution 2 —
Other way is to use “zerofree”, so let’s open a terminal and let’s go ready with super user:
su root
install zerofree (thanks Ron Yorston):
apt-get install zerofree
reinit system:
init 1
remount disks in readonly mode because zerofree works only on readonly disks, my disk is /dev/hda1 (check it with “mount” command) and you have to declare filesystem type:
mount -n -o remount,ro -t ext3 /dev/hda1 /
zero free space:
zerofree /dev/hda1
…after hours and hours… … and hours …
… and, but are you working or what? … … and done! Yeahhhhhhh
Last simple step, reboot:
reboot
Done!
From linux host launch:
VBoxManage modifyvdi /mypath/mydisk.vdi compact
From win host launch:
VBoxManage.exe modifyvdi c:\mypath\mydisk.vdi compact
