Summary:

This is tech-debt for an existing customer used supported feature. We need to complete docs and add tests to existing job to improve our test coverage and supportability. Because this has a customer facing doc change with new content, we use the feature Jira type

Existing Feature Overview 
There is an optimisation path when using Glance backed by cinder. This optimisation allows volume created from image requests to be cloned i.e backend assisted avoid image to be downloaded from Glance API. only works if both in same pool

This Jira feature tracks the missing productization of this optimisation.

• Who benefits from this Feature, and how? 
  • Any customer using Glance backed by Cinder
  • In particular
    • Distributed Zones
    • DCN 3rd party when/if productised
• What is the difference between today’s current state and a world with this Feature?
  • Creating a volume from image can take lot of time as it needs to be downloaded from Glance API

Goals 

• Provide CI coverage and docs for this feature that is already enabled by default
• Deliver in the 18.0z release stream - doesn't need to wait for FR release if limited to docs and addition of tests to existing CI jobs

Documentation Considerations:

• On by default, no config changes needed. Need to document the optimization is on by default and only enabled in specific scenarios such as it only works if both in same pool.

Testing Considerations:

• https://docs.google.com/document/d/1wPw0gbYEmAFQw3BGJiJUqJiYduvN1lqPwNn3cJ0c-5s/edit?tab=t.0#heading=h.1nobcw3xa9dn
• can be automated, verify it works by using the logs

Done - Acceptance Criteria

• CI automated testing of the feature in a gating job (component CI may be sufficient)
• Document feature existence and limitations
• Add to support enablement plans if needed

Questions to Answer 

What is the defined the support scope?

• We did early manual testing, code is already in place in RHOSO18. However it is currently limited to a shared storage pool between Glance & Cinder.  That is the only supported case for this feature tech debt

What about cross-pool?

• For cross pool support where Glance and Cinder use a different host@backend#pool we need to backport patches from upstream. https://issues.redhat.com/browse/RHOSSTRAT-1000- 

How will NFS use bug be tracked

• See BugEpic linked below