On Wed, Aug 10, 2016 at 7:53 AM, Yedidyah Bar David <didi@redhat.com> wrote:
> On Tue, Aug 9, 2016 at 8:39 PM, Budur Nagaraju <nbudoor@gmail.com> wrote:
>> HI
>>
>> How to upgrade oVirt3.5 to 4 ? am using centos6.7.
>
> First upgrade or reinstall your hosts with el7.
> oVirt 3.6+ does not provide packages for el6. el6 hosts will
> still work, but easiest to upgrade to el7 in 3.5.
>
> If you are using hosted-engine, you can follow [1].
>
> Then upgrade to 3.6 using regular docs [2].
>
> In 4.0, the engine is also el7 only. To upgrade, use engine-backup
> to backup, then reinstall the machine with el7, then restore. I do
> not think we have a special page for this, but you can follow the
> doc text of [3], which is also copied in the 4.0 release notes [4].
> Please review [5] for more information about engine backup and restore.
> If you using hosted-engine, you can use the new upgrade tool to upgrade
> the engine vm using the engine appliance. Not sure that's properly
> documented either, see also [6]. Also note that this bug is for 4.0.2,
> to be released soon.

We have this:
https://www.ovirt.org/develop/release-management/features/hosted-engine-migration-to-4-0/