I think the alternative exporting the storage domain is perfect. Can you confirm that i
have to reinstall the Hypervisors 3.4 (based on centos 6) to reach the 3.5? On the upgrade
helper (3.4 to 3.5 ) i have found this "
Upgrade hosts to 3.5.
Reinstall with RHEL7 based hosts. Follow this solution:
Directly upgrading RHEV hosts from RHEL/RHEV-H 6 to RHEL/RHEV-H 7 is not supported:
Change Compatibility Level (CL) of the cluster(s) and the Data Center to 3.5:"