Cloned from: https://blog.sleeplessbeastie.eu/2012/04/29/virtualbox-convert-raw-image-to-vdi-and-otherwise/
VirtualBox – convert RAW image to VDI and otherwise
VirtualBox command-line interface (VBoxManage) provides an easy way to convert raw disk image to the VDI/VMDK format and otherwise.
Let’s assume that we have raw image of the sdb device:
sudo dd if=/dev/sdb of=./sdb.raw
To use it with VirtualBox we need to convert it to the VDI format:
VBoxManage convertdd sdb.raw sdb.vdi --format VDI
To use it with VMware we need to convert it to the VMDK format:
VBoxManage convertdd sdb.raw sdb.vmdk --format VMDK
Convert between VDI/VMDK formats:
VBoxManage clonehd sdb.vdi sdb.vmdk --format VMDK
VBoxManage clonehd sdb.vmdk sdb.vdi --format VDI
Convert to the RAW image:
VBoxManage clonehd sdb.vdi sdb.raw --format RAW
Alternative solution to get back raw image after applying modifications is to use qemu-img command from qemu package:
qemu-img convert -f vmdk sdb.vmdk -O raw sdb.raw
Now we can write image to the device:
sudo dd if=./sdb.raw of=/dev/sdb
This worked for me, thanks man.