It's as simple as below where you just specify the dev device of the CDROM which is usually /dev/sr0. You can boot actual bootable discs like Windows, Linux, etc straight from a physical drive this way.
sudo qemu-system-x86_64 -cdrom /dev/sr0 -m 4096
........
I like dd, although it only reads it, usually a read test of the entire disk will uncover if your hard drive is bad in some parts. This is a good thing to do at least once a month, a lot of times bizarre program behavior, laginess and crashing/unnmounting problems etc.. are due to a failing disc and SMART won't know it or indicate a problem:
We must also remember there's never a guarantee, I've found that ever since we moved to larger and more platters per drive with 1TB drives........