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Showing posts from July, 2023

Cleaning and resizing VM VirtualBox VDI Virtual Machine Disk

 You have to do the following steps: Run defrag in the guest (Windows only) Nullify free space: With a Linux Guest run this: dd if=/dev/zero of=/var/tmp/bigemptyfile bs=4096k ; rm /var/tmp/bigemptyfile Or: telinit 1 mount -o remount,ro /dev/sda1 zerofree -v /dev/sda1 With a Windows Guest, download SDelete from Sysinternals and run this: sdelete.exe c: -z (replace C: with the drive letter of the VDI) Shutdown the guest VM Now run VBoxManage's modifymedium command with the --compact option: With a Linux Host run this: vboxmanage modifymedium --compact /path/to/thedisk.vdi With a Windows Host run this: VBoxManage.exe modifymedium --compact c:\path\to\thedisk.vdi With a Mac Host run this: VBoxManage modifymedium --compact /path/to/thedisk.vdi This reduces the vdi size.