[ovirt-users] Why difference between upgrade paths 3.6 to 4.0.x between RHEV and oVirt?

[Barak Korren]

On 23 December 2016 at 18:10, Gianluca Cecchi <gianluca.cecchi at gmail.com> wrote:
>
> Is there any particular technical reason for this substantial difference?
> Clearly they are not the same sw but it seems strange to me this
> discrepancy.

This is because RHEV 3.6 engine was only supported on RHEL6 while RHV
4.0 engine is only supported on RHEL7, so an upgrade (read:
re-installation) of the underlying OS (And hence, the whole engine
software stack) is required.

oVirt 3.6 engine OTOH was also tested on CentOS 7, so you can upgrade
it in-place to oVirt 4.0.
Note: oVirt 4.0 engine is not supported on CentOS 6 at all, so you
shouldn't try to upgrade in-place on CentOS 6.

> Suppose I have a mix of oVirt and RHEV environments it could be simpler to
> have a common path, where possible.
>
> For example, can I also use the documented RHEV approach for oVirt? At what
> extent?

Yes you can. The RHV upgrade path was also tested on oVirt, just keep
the CentOS version you are running oVirt on as close as possible to
the RHEL versions you are running RHV on...

Having said the above, I know vaguely that Red Hat has some
all-on-nothing rules when it comes to licensing, so a mixed RHV/oVirt
environment may not meet the RHEL/RHV licensing terms... Then again,
I'm not a licensing expert...

-- 
Barak Korren
bkorren at redhat.com
RHCE, RHCi, RHV-DevOps Team
https://ifireball.wordpress.com/