Bug 1466557

Summary:	Compatibility Level also depends on vdsm version
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Germano Veit Michel <gveitmic>
Component:	Documentation	Assignee:	Tomas Dosek <tdosek>
Status:	CLOSED CURRENTRELEASE	QA Contact:	rhev-docs <rhev-docs>
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	dberry, fgarciad, lsurette, mkalinin, rbalakri, srevivo, tdosek, usurse, ykaul, ylavi
Target Milestone:	ovirt-4.1.6	Keywords:	Triaged
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-01-30 18:25:06 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Docs	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Germano Veit Michel 2017-06-30 02:20:42 UTC

Description of problem:

The documentation[1] 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 [1]:

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] RHVH-4.0-20161018.0-RHVH-x86_64
[B] rhev-hypervisor7-7.2-20161220.0
[C] rhev-hypervisor7-7.2-20160219.0

[A] uses vdsm 4.18 (CL 4.0)
[B] uses vdsm 4.17 (CL 3.6)
[C] uses vdsm 4.16 (CL 3.5)

So:

[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).

Another example:

7.3 is compatible with 3.6, 4.0 and 4.1. We have these images which are all based on 7.3:

[D] RHVH-4.1-20170616.0-RHVH-x86_64
[E] RHVH-4.0-20170308.0-RHVH-x86_64
[F] rhev-hypervisor7-7.3-20170615.0
[G] RHVH-3.6-20170618.1-RHVH-x86_64
But:

[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)

So:

[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)

Documentation[1] quote:

"...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 [1] is missing Supported Compatibility Level 3.6 for RHEL 7.3.

[1] https://access.redhat.com/support/policy/updates/rhev

Comment 3 Marina Kalinin 2017-06-30 21:09:03 UTC

*** Bug 1466550 has been marked as a duplicate of this bug. ***

Comment 5 Marina Kalinin 2018-01-30 18:25:06 UTC

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/