Need to refine - this feature is already in use and on by default, ensure CI and review/add docs - only works if both in same pool

Feature Overview (mandatory - Complete while in New status)
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.

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 ** 

Documentation Considerations:

• On by default, no config changes needed. need to document the optimization is on by default and only enabled in specific scenarios

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 define 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. -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-