/dev/rhel/root does not exist

I moved a redhat install from VirtualBox to XenServer, and cannot get it to boot. It starts booting, but then end up with dracut warning that /dev/rhel/root does not exist. The confusing thing is if I boot with recovery option, it does find root fine.

Another clue when it doesn't boot and gest into emergency mode, doing 'lvm lvs' returns nothing, but otherwise looks good. The only difference between 'lvm pvs' in recovery mode vs. how it looks in VirtualBox is the device is /dev/xvda2 vs. /dev/sda2 . What do I need to do update so I can boot in regular boot?

Thanks.