Comment 5 for bug 1877418

I agree, the program doesn't stop you from doing such things. It should work without error, but it might be slow. Just offering some advice you may not want to use it like this.

Try to reproduce with qcow2 and qemu-nbd to see if the problem is with our support of the disk image format or if it's a problem with e.g. the access patterns and qemu-nbd itself, for instance.