[caraboga]

Openstack doesn't have the in-product hooks to detect hardware failures on the host machine to prompt an automatic, vm-state preserving live migration to other hosts.

If you are using kvm w.r.t. openstack, the vm machine actually is suspended by way of acpi, then moved, then unfrozen again. VMware doesn't do that in vmotion. All your problems with clock skew, dropping of network traffic are lessened (they don't completely go away) with vmotion.