[ovirt-users] compatibility relationship between datacenter, ovirt and cluster

[Itamar Heim]

On 04/10/2014 10:50 PM, Tamer Lima wrote:
> Hi,
>
>
> yesterday my ovirt was 3.3
> my datacenter and cluster (compatibility version) was aligned with ovirt
> 3.3
>
>
> today my ovirt is now 3.4.
> and my datacenter and cluster (compatibility version) remains 3.3  (with
> the option enabled to change for 3.4)
>
> browsing the ovirt admin page I see 2 occurrences of ovirt version:
> datacenter tab  = 3.3
> cluster tab  =3.3
>
>
>
> I would like to understand what means all these versions, the same
> version for a lot of important things, and how my ovirt works/behaves
> using different versions.
>
> all my doubts together :
> What means datacenter in version 3.3(or lower version) when ovirt is 3.4  ?
> what means cluster in version 3.3 when ovirt is 3.4?
> what means change the "compatibility version" for datacenter?
> what means change the "compatibility version" for cluster?

Gianluca replied with links for specific features.
I'll reply on the general concept:
- a host can be upgraded to a specific 3.x version. it can be in any
   3.y cluster which is <= 3.x
   once the host is upgraded, 3.x host-level features can be used
- a cluster can be upgraded to 3.x once all active hosts in it are at
   least with 3.x.
   once the cluster is upgraded, 3.x cluster-level features can be used
- a data cetner can be upgaeded to 3.x once all clusters in it are at
   least with 3.x
   once the DC is upgraded, 3.x DC-level features can be used

i don't think we have it clearly documented per feture if it is host 
level, cluster level or DC level. when in doubt, ask...