I created a 60 GB raw disk using qemu-img convert, and qemu-img info confirms it is a raw file format. It worked fine in KVM. When I go in ESXi to create a new VM from existing virtual disk, and browse to the disk in the datastore, it is not visible (using the compatible disk mask that VMWare uses .vmdk,.raw, etc). ESXi claims to support raw file format for virtual disks, what gives?
In that case, you are trying to access a raw disk (raw device, not raw device file), not a raw disk file as qemu calls it. Confusing terminology, I guess. Take a look at this: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=995
Still it is not what you are looking for, most likely, but I am not sure esxi suports the actual raw disk file as used in kvm etc. You can try to convert these to vmdk with qemu-img however.