ref: https://tsaikd.org/blog/2010/03-14-VirtualBox-%E7%9B%B4%E6%8E%A5%E5%AD%98%E5%8F%96%E5%AF%A6%E9%AB%94%E7%A1%AC%E7%A2%9F-or-USB/
- linux
VBoxManage internalcommands createrawvmdk -filename ~/winxp.vmdk -rawdisk /dev/sda -partitions 1
- windows
VBoxManage internalcommands createrawvmdk -filename D:\VMHD\disk_C.vmdk -rawdisk \\.\PhysicalDrive0 -partitions 5