Feature Overview

As a vSphere infrastructure administrator, I want to deploy OpenShift on vSphere and be able to set the vSphere DRS affinity rules for the control plane nodes (to run on different hypervisors) for high availability and better resiliency.

This feature focuses on how to add vSphere DRS anti-affinity rules with UPI via documentation. Support with IPI is out of scope and will be addressed in a future release.

 This is Phase 1 of 2 Phases:

• Phase 1 (UPI) - Define (Document) how to add vSphere DRS anti-affinity rules with UPI [Target OCP 4.12].
• Phase 2 (IPI) - Add vSphere DRS anti-affinity rules support for IPI in Day 1 [Future OCP release - TBD].

Goals

Provide support for vSphere DRS anti-affinity rules for UPI.

Requirements

• This Section:* A list of specific needs or objectives that a Feature must deliver to satisfy the Feature.. Some requirements will be flagged as MVP. If an MVP gets shifted, the feature shifts. If a non MVP requirement slips, it does not shift the feature.

(Optional) Use Cases

This Section:

• Main success scenarios - high-level user stories
• Alternate flow/scenarios - high-level user stories
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Questions to answer…

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Out of Scope

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Background, and strategic fit

The existing OpenShift Installer (4.11 and earlier) creates all machines/nodes on the same hypervisor (this is where they would prefer anti affinity rules). They would like to have each node created on separate hypervisor upon installation. There is no solution for this at the moment automatically by OpenShift. To do this you must wait for the new node to be installed by OpenShift, then place the rule in VMware because VMware will not know the new node's uuid beforehand.

Once the cluster is up they want to add another node to the cluster, they do not see an option where they can tell openshift installer where to place the new node.

Related references

• RFE-1792 - Need for OpenShift VMware anti-affinity rule feature
• RFE-1402 - Ability to set the CPU and memory reservations for VMs in the install.config during the ocp4 IPI install
• SPLAT-391 - [spike][vsphere] Research creating DRS anti-affinity rules as part of installation

Assumptions

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Customer Considerations

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Documentation Considerations

Questions to be addressed:

• What educational or reference material (docs) is required to support this product feature? For users/admins? Other functions (security officers, etc)?
• Does this feature have doc impact?
• New Content, Updates to existing content, Release Note, or No Doc Impact
• If unsure and no Technical Writer is available, please contact Content Strategy.
• What concepts do customers need to understand to be successful in [action]?
• How do we expect customers will use the feature? For what purpose(s)?
• What reference material might a customer want/need to complete [action]?
• Is there source material that can be used as reference for the Technical Writer in writing the content? If yes, please link if available.
• What is the doc impact (New Content, Updates to existing content, or Release Note)?