Hello Luigi, You can upgrade to the latest minor of 3.4 and then upgrade step by step to each major (3.5 3.6 4.0 4.1 4.2 4.3) It's a long procedure, requires several downtimes for upgrading the cluster compatibility level, but shouldn't be so hard. Luca Il dom 1 dic 2019, 12:05 <lu.alfonsi(a)almaviva.it&gt; ha scritto:

On Mon, Dec 2, 2019 at 3:19 PM <lu.alfonsi(a)almaviva.it&gt; wrote: You'll need to reinstall the hypervisors when upgrading from 3.6 to 4.0, because changes the OS release from centos/rhel 6 to centos/rhel 7. And maybe you'll require to do the same with the engine server. An alternative procedure can be to stop all the vms on the 3.4 cluster, detach the storage volumes and attach the storage volumes on a new cluster 4.3, reimporting back all the vms after recreating the networks. I'm not sure this can work directly with 3.4 (maybe you require to upgrade at least to 3.5), because is a very ancient release, but maybe you can upgrade up to 3.6 and this should work. With this procedure you can upgrade with a single step, but with a longer downtime. Someone with more experience can confirm this? Luca -- "E' assurdo impiegare gli uomini di intelligenza eccellente per fare calcoli che potrebbero essere affidati a chiunque se si usassero delle macchine" Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716) "Internet è la più grande biblioteca del mondo. Ma il problema è che i libri sono tutti sparsi sul pavimento" John Allen Paulos, Matematico (1945-vivente) Luca 'remix_tj' Lorenzetto, http://www.remixtj.net , <lorenzetto.luca(a)gmail.com&gt;

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: https://access.redhat.com/articles/1390733 Directly upgrading RHEV hosts from RHEL/RHEV-H 6 to RHEL/RHEV-H 7 is not supported: https://access.redhat.com/solutions/2752051 Change Compatibility Level (CL) of the cluster(s) and the Data Center to 3.5:" Thanks Luigi

Hello, as far as i remember from my certification course, ovirt/rhv 3.5 is still based on 6. So you can easily upgrade in place and then make detach/attach. Luca On Tue, Dec 3, 2019 at 9:13 AM <lu.alfonsi(a)almaviva.it&gt; wrote: -- "E' assurdo impiegare gli uomini di intelligenza eccellente per fare calcoli che potrebbero essere affidati a chiunque se si usassero delle macchine" Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716) "Internet è la più grande biblioteca del mondo. Ma il problema è che i libri sono tutti sparsi sul pavimento" John Allen Paulos, Matematico (1945-vivente) Luca 'remix_tj' Lorenzetto, http://www.remixtj.net , <lorenzetto.luca(a)gmail.com&gt;

Hello, as far as I know yes. If IIRC, 3.5 was the first release supporting attach/detach of volumes, using OVF_STORE: https://www.ovirt.org/develop/release-management/features/storage/imports... Luca On Thu, Jun 11, 2020 at 5:48 PM <lu.alfonsi(a)almaviva.it&gt; wrote: -- "E' assurdo impiegare gli uomini di intelligenza eccellente per fare calcoli che potrebbero essere affidati a chiunque se si usassero delle macchine" Gottfried Wilhelm von Leibnitz, Filosofo e Matematico (1646-1716) "Internet è la più grande biblioteca del mondo. Ma il problema è che i libri sono tutti sparsi sul pavimento" John Allen Paulos, Matematico (1945-vivente) Luca 'remix_tj' Lorenzetto, http://www.remixtj.net , <lorenzetto.luca(a)gmail.com&gt;