That sounds like RHEL 6 (or CentOS).
Sounds like one resolved symlinks while the other did not. Maybe it's worth enhancing libvirt to allow all names that resolve to the same file, rather than just the exact spelling used? At any rate, we solved
Yup, CentOS 6.3. I should have mentioned that. this. Maybe but I don't think it is a high priority. Libvirt is pretty awesome the way it is. Yup, it is solved, thank you again.
Alas, your qemu is too old. Red Had did not ship live disk snapshots in RHEL 6.3; to get that functionality, you need RHEV 3.0. Wish I had better news, but at this point, an in-guest dd to a hot-plugged alternative disk is the best I can think of, since there's nothing you can do from the host side without qemu support.
That's unfortunate but at least I understand why.
Hope it works for your guest in question, then. Good luck.
Thank you. This mailing list has been great. Regards, Joe