I upgrade our opennebula kvm cluster from 5.6.1 to 5.8.1 following the notes from here http://docs.opennebula.org/5.8/intro_release_notes/upgrades/upgrade_56.html
Everything was fine up to the the " Update the Drivers" and the sync command.
$ onehost sync
Failed to update the following hosts:
The --force option gives me the same result.
The cluster is working fin for now, but I am worried because the sync did not complete.