What are the differences between ata-disk and virtio-block in mvisor's configuration?

[antermin]

I imagine that ata-disk means using a disk image file for VM while virtio-block means using a disk (e.g. /dev/sda) for the VM.

However, in the sample configuration, the image parameter of both classes is a path to a file:

mvisor/config/sample.yaml

Lines 37 to 39 in 8f9f37d

	- class: ata-disk
	image: /data/empty.qcow2
	snapshot: No

mvisor/config/sample.yaml

Lines 44 to 46 in 8f9f37d

	# - class: virtio-block
	# image: /data/empty.qcow2
	# snapshot: No

Could you please explain virtio-block, such as its function and its parameters? Thank you.

[78]

ata-disk and virtio-block are two different types of emulated block devices.

The main difference is that ata-disk emulates a legacy ATA/AHCI controller (fully emulated), while virtio-block is a paravirtualized VirtIO block device (much lower overhead).

Both can use the same disk image file as backend storage.