VBoxManage clonemedium "source.vmdk" "cloned.vdi" --format vdi VBoxManage modifymedium "cloned.vdi" --resize 51200 VBoxManage clonemedium "cloned.vdi" "resized.vmdk" --format vmdk
To complete things you need to resize the drive too! To achieve this, you might want to download gparted iso and boot from that iso to resize your drive (select the iso from within the virtualbox settings).
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