Red Hat Bugzilla – Bug 1466557
Compatibility Level also depends on vdsm version
Last modified: 2018-03-04 23:08:00 EST
Description of problem:
The documentation is a bit superficial stating that RHEL releases are directly related to supported cluster levels.
It can confuse customers while planning upgrades, resulting in unexpected extra steps to be taken.
For example, from the last table of :
RHEL 7.2 is compatible with RHV 3.5, 3.6. 4.0.
This is incomplete information. RHEL 7.2 is the base OS for several releases of RHEV-H/RHV-H/RHEL-H. For example, based on RHEL 7.2 we have:
[A] uses vdsm 4.18 (CL 4.0)
[B] uses vdsm 4.17 (CL 3.6)
[C] uses vdsm 4.16 (CL 3.5)
[B] is not compatible with 4.0
[C] is not compatible with 3.6 and 4.0
And I'm afraid installing [A] on 3.5 will yield a wrong vds_type.
Therefore stating that 7.2 is compatible with 3.5, 3.6 and 4.0 is misleading, as we have at least 3 completely different images that are all 7.2 but ship with very different packages, especially the management agent (vdsm).
7.3 is compatible with 3.6, 4.0 and 4.1. We have these images which are all based on 7.3:
[D] uses vdsm 4.19 (CL 4.1)
[E] uses vdsm 4.18 (CL 4.0)
[F] uses vdsm 4.17 (CL 3.6)
[G] uses vdsm 4.17 (CL 3.6)
[E] is not compatible with 4.1
[F] is not compatible with 4.0 and 4.1
[G] is not compatible with 4.0 and 4.1, although easy to upgrade (NGN)
"...corresponding Red Hat Enterprise Linux release with the appropriate management agent installed."
We need to clarify:
* what are appropriate versions?
* what is the package involved (vdsm)
Also note that  is missing Supported Compatibility Level 3.6 for RHEL 7.3.
*** Bug 1466550 has been marked as a duplicate of this bug. ***
Germano, I will close the bug for now, since the following changes has been made and we consider them sufficient at this point.
Life cycle has been made more clear. Specifically see table under "Red Hat Hypervisor Upgrade and Support Policy" : https://access.redhat.com/support/policy/updates/rhev/
And for correlation between RHVH release and vdsm version, we should refer to package manifest guide: https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.1/html/package_manifest/