SF should check that a disk base is a valid image format

[mikalstill]

SF should check that a disk base is a valid image format

[mikalstill]

I think this one might be hard. qemu-img can tell us that a file is RAW (for example an HTML 404 page), but that is also a valid disk format. I am unsure how we test if it is bootable programmatically.

[mandoonandy]

Maybe this is a naive approach?
Check for RAW images that are too small to be a realistic disk image, also check that it contains HTML tags (or maybe 'not found' text).