The iDRAC/iLO/BMC/IMM mounting systems seems to work in the same way
that the qemu uses the iso image to boot. Whatever causes 'real'
hardware to fail in certain cases does not seem to affect the remote
mounting systems or the qemu.
I have used the remote booting quite a lot and at least once with an
image which wasn't supposed to work with a real DVD image. It worked
fine in those cases.
This is great info, thanks a lot.