+++ This bug was initially created as a clone of Bug #1505887 +++
As mentioned in https://bugzilla.redhat.com/show_bug.cgi?id=1505887#c7 we need to unset RHEL release before attempting to upgrade vdsm. Otherwise, the new vdsm with its dependencies of new RHEL would not be installable.
I suggest to run `vdsm-tool remove-config --module subscription_manager` before upgrading vdsm. vdsm-tool may not be found (if vdsm is not yet installed); the module may not be found (if the installed vdsm version is too old). Those two error should be ignored by host-deploy.
We must verify whether the upgrade manager flow require similar handling just in order to check whether an upgrade of vdsm is available.