Bug 1420402

Any workaround to not require customers to do this stepped RHV-H upgrade to 4.1?

(In reply to Yaniv Dary from comment #1)
> Any workaround to not require customers to do this stepped RHV-H upgrade to
> 4.1?

This just impacts customers who have just RHEL-H 3.y hosts.

Two options here:
A. In 4.0 the capability to add an additional hosted-engine host via CLI was deprecated but it was still there so simply add (or upgrade) a 4.0 RHEV-H host from CLI as an hosted-engine host and perform the upgrade of the engine VM from 3.6/el6 to 4.0/el7 from there.
B. Use RHEL on one additional host: deploy the host as a 3.6 one HE one via CLI getting the rpms from 7Server-RHEV-Agents-7 channel; then add 7Server-RHEV-4-Agents-7 channel on that host in order to get ovirt-hosted-engine-setup-2.1.z (and it's dependencies) and upgrade the host. At this point the user can run 'hosted-engine --upgrade-appliance' to upgrade the engine appliance from 3.6/el6 to 4.0/el7.

Adding additional context for the docs:

The instructions for upgrading a SHE installation from 3.6 to 4.0 must be updated when RHV 4.1 becomes generally available, to account for a scenario in which a user wants to update 3.6 RHEV-H self-hosted engine hosts to 4.1 RHVH.

Although we only support upgrading/migrating from one version to the next version (rather than 3.6 to 4.1), we do support 3.6 compatibility level for clusters. Users who have a self-hosted engine running on 3.6-compatible RHEV-H hosts may want to upgrade to 4.1, and then at some point migrate those hosts to the new RHVH (which requires reinstallation rather than a true upgrade/migration). They will encounter a scenario where they are unable to add the RHVH host to the 3.6 self-hosted engine, because the 3.6 SHE only supports addition of self-hosted engine hosts via the CLI, and this functionality is removed in 4.1.

Suggested flow from Yaniv Dary (with additional info added by lbopf):

If you are running a 3.6 cluster, do not install the 4.1 release of RHVH straight away. Because 4.1 removes the addition of hosts to the SHE cluster via CLI (instead UI/API only), you won't be able to add the host back to the cluster, because the 3.6 manager only supports addition of hosts via CLI.

You should first upgrade one RHEV-H host in the self-hosted engine cluster (that is, the hosts that the SHE runs on) from the legacy RHEV-H to the 4.0 release of RHVH. This is a reinstall of the host and is not considered a upgrade, so the host will not be part of the SHE cluster after reinstall.

To work around this, add the host to the SHE cluster via CLI (still supported in 4.0, although deprecated) and run the --upgrade-appliance command so the manager will migrate from 3.6 to 4.0.

After that, other legacy RHEV-H hosts can be upgraded to 4.1 directly (as 4.1 has 3.6 compatibility) and can be re-added to SHE cluster via API/UI.

Assigning to Tahlia for review.

Tahlia, the requirement for this bug is chiefly to clearly outline the workflow a user has to take in moving from 3.6 RHEV-H self-hosted engine hosts to (eventually) 4.1 RHVH self-hosted engine hosts. Comment 3 attempts to explain this as clearly as possible.

Because most of the workflow is in the 3.6->4.0 upgrade, I imagine that this content would be best placed in the 4.0 Upgrade Guide, and referenced from the 4.1 Upgrade Guide.

Let me see if I understand the start and end goal here:
* You start with a 3.6 SHE env.
* You end with a 4.1 SHE env. The Manager and one host have a brief stop at 4.0 along the way, but the rest of the hosts can jump straight to 4.1.
* This only applies if all your hosts are RHEV-H, as RHEL hosts don't have this problem. 

The basic steps, IIUC: 

1. Install a new 4.0 RHVH (or remove a 3.6 RHEV-H and "upgrade" it to 4.0 RHVH)

2. Add it to the 3.6 SHE env using "hosted-engine --deploy" (the steps are here: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.6/html-single/Self-Hosted_Engine_Guide/index.html#chap-Installing_Additional_Hosts_to_a_Self-Hosted_Environment but it may not be worth linking to as it's not quite correct for 4.0 RHVH. Better to just write some new steps. Actually, now that I think about it, the 4.0 upgrade section, linked in the next step, should probably specify to add the new RHVH host using the CLI?)

3. Upgrade the Manager from 3.6 to 4.0 using these steps: https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html-single/self-hosted_engine_guide/#Upgrading_a_RHEV-H-Based_Self-Hosted_Engine_Environment (from step 3 onwards)

4. Remove each 3.6 RHEV-H and reinstall as 4.1 RHVH, and add to the 4.0 SHE using these steps: https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html-single/self-hosted_engine_guide/#chap-Installing_Additional_Hosts_to_a_Self-Hosted_Environment

5. Upgrade the Manager to 4.1 (the steps are here: https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.1/html/self-hosted_engine_guide/upgrading_the_self-hosted_engine but should they use "hosted-engine --upgrade-appliance" instead of manually changing the repos and everything? might need to be updated)

6. Update the remaining 4.0 host to 4.1 with the Upgrade button in the UI or "yum update".

I think this would be best placed as a new section after the regular upgrade section in the 4.1 Self-Hosted Engine Guide, with links to the appropriate 4.0 sections.

Please let me know if I've misunderstood anything.

Yaniv, am I on the right track in my comment above?

(In reply to Tahlia Richardson from comment #5)
> Let me see if I understand the start and end goal here:
> * You start with a 3.6 SHE env.
> * You end with a 4.1 SHE env. The Manager and one host have a brief stop at
> 4.0 along the way, but the rest of the hosts can jump straight to 4.1.
> * This only applies if all your hosts are RHEV-H, as RHEL hosts don't have
> this problem. 
> 
> The basic steps, IIUC: 
> 
> 1. Install a new 4.0 RHVH (or remove a 3.6 RHEV-H and "upgrade" it to 4.0
> RHVH)

Ack

> 
> 2. Add it to the 3.6 SHE env using "hosted-engine --deploy" (the steps are
> here:
> https://access.redhat.com/documentation/en-US/
> Red_Hat_Enterprise_Virtualization/3.6/html-single/Self-Hosted_Engine_Guide/
> index.html#chap-Installing_Additional_Hosts_to_a_Self-Hosted_Environment but
> it may not be worth linking to as it's not quite correct for 4.0 RHVH.
> Better to just write some new steps. Actually, now that I think about it,
> the 4.0 upgrade section, linked in the next step, should probably specify to
> add the new RHVH host using the CLI?)

Ack

> 
> 3. Upgrade the Manager from 3.6 to 4.0 using these steps:
> https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/
> html-single/self-hosted_engine_guide/#Upgrading_a_RHEV-H-Based_Self-
> Hosted_Engine_Environment (from step 3 onwards)

This is the flow for 3.6->4.0 migration:

https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html-single/self-hosted_engine_guide/#Upgrading_the_Self-Hosted_Engine

> 
> 4. Remove each 3.6 RHEV-H and reinstall as 4.1 RHVH, and add to the 4.0 SHE
> using these steps:
> https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/
> html-single/self-hosted_engine_guide/#chap-
> Installing_Additional_Hosts_to_a_Self-Hosted_Environment

Ack

> 
> 5. Upgrade the Manager to 4.1 (the steps are here:
> https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.1/
> html/self-hosted_engine_guide/upgrading_the_self-hosted_engine but should
> they use "hosted-engine --upgrade-appliance" instead of manually changing
> the repos and everything? might need to be updated)

To update the manager they need to enable channels, yum update and engine-setup just like any minor.

> 
> 6. Update the remaining 4.0 host to 4.1 with the Upgrade button in the UI or
> "yum update".
> 
> I think this would be best placed as a new section after the regular upgrade
> section in the 4.1 Self-Hosted Engine Guide, with links to the appropriate
> 4.0 sections.
> 
> Please let me know if I've misunderstood anything.

The flow is also affected by:
https://bugzilla.redhat.com/show_bug.cgi?id=1445161
As this adds a NGN RHV-H for 3.6 and the steps are like RHEL which don't need these extra step. We should recommend to use that everywhere we can.

Simone, please keep me honest.

(In reply to Yaniv Dary from comment #7)
> > 
> > 3. Upgrade the Manager from 3.6 to 4.0 using these steps:
> > https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/
> > html-single/self-hosted_engine_guide/#Upgrading_a_RHEV-H-Based_Self-
> > Hosted_Engine_Environment (from step 3 onwards)
> 
> This is the flow for 3.6->4.0 migration:
> 
> https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/
> html-single/self-hosted_engine_guide/#Upgrading_the_Self-Hosted_Engine
> 

If it's a newly-installed RHVH 4.0, then we don't need to enable the rhv-4-mgmt-agent repo, or install/upgrade ovirt-hosted-engine-setup, so https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html-single/self-hosted_engine_guide/#Upgrading_the_Self-Hosted_Engine isn't quite right.

https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html-single/self-hosted_engine_guide/#Upgrading_a_RHEV-H-Based_Self-Hosted_Engine_Environment describes the exact scenario we're talking about here, i.e. installing a new RHVH 4.0 and adding it to a 3.6 SHE env, then upgrading the Manager to 4.0. As far as I can tell, all that needs to be changed is that step 2 should specify to use the CLI instead of linking to the 4.0 instructions for adding an additional SHE host, and step 4 can (I hope?) be replaced with yum install rhvm-appliance.

Reviewed and verified.

Now published at https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.1/html/self-hosted_engine_guide/upgrading_a_rhev-h_she_to_rhvh

Updated 4.0 step also published at https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.0/html/self-hosted_engine_guide/upgrading_a_rhev-h-based_self-hosted_engine_environment