Goal:

Customer C42 uses Dell EMC's PowerFlex for cinder volume storage, and they also use cinder's image volume cache feature. C42 is aware of the PowerFlex "vtree" limitation which negatively impacts the image volume cache when there are are large number of volumes (and their snapshots) associated with an image volume cache entry.

C42 proposed an enhancement that limits the "life" of a cache entry based on the size of its vtree, so that existing cache entries can be deleted and replaced by a fresh cache entry well before the vtree reaches the PowerFlex limit.

Red Hat and Dell agree C42's proposal has merit, and further agreed that Red Hat would implement the required code changes in the PowerFlex driver, and Dell would review and test the code.

Acceptance Criteria:

• The code patch developed by Red Hat and  tested by Red Hat is accepted into the upstream cinder project.
• The patch is back ported to a downstream RHOSO 18 release.
• Can/Should we include C42 by having them test a preview?

Open questions:

• TBD