RAW images, though simple to work with, carry the disadvantage of increased disk usage on the host OS. One option we have is to convert the image into the QCOW2 format which uses zlib^[14] compression and optionally allows your disks to be secured with 128 bit AES encryption^[15]. TODO: Explain how QCOW2 only uses as much space as there is data in the image. Also talk about sparse file systems

$ qemu-img convert -O qcow2 original-image.raw image-converted.qcow

$ qemu-img info image-converted.qcow
image: image-converted.qcow
file format: qcow2
virtual size: 10G (10737418240 bytes)
disk size: 140K
cluster_size: 65536

Here's how to do the last example, but in reverse.

$ qemu-img convert -O raw image-converted.qcow image-converted-from-qcow2.raw

$ qemu-img info image-converted-from-qcow2.raw
image: image-converted-from-qcow2.raw
file format: raw
virtual size: 10G (10737418240 bytes)
disk size: 0

	Note
	When converted to the RAW format the image has the potential to take up much more disk space than before. RAW images may use up up their allocated space immediately, whereas QCOW images will grow to their pre-determined maximum size over time.