Hi Team

Description: 

Customer using Cinder backend NetApp. Customer facing issue when they check FlexVol size that report total size not how much is used.

Customer Impact

1. The customer is performing  VM backup, which leverages OpenStack features such as Cinder snapshots and temporary LUN creation to transfer backups to secondary storage. Within this workflow, Cinder blocks an equivalent capacity of the Cinder snapshot for mounting and reading backup data. This occurs even though the underlying usage at the storage level remains unchanged due to storage efficiency.
2. As a result, the customer must ensure the availability of 50% of their storage capacity for backup jobs, preventing them from utilizing the entire storage capacity for production.
3. This is a critical ask as customer is not able to consume available storage leading to resource wastage and in some case outages too.

Ask: To review the changes part of the below patch and also apply the patch on customer environment  https://review.opendev.org/c/openstack/cinder/+/968831

Reason: We have released a new patch to mitigate the challenge which needs to be reviewed by RedHat and help to productionise the same for the customer.

Next steps:

Requesting Redhat team to:

1. Review this patch from core reviewers
2. Provide set of steps(for RHOSP environment) required to enable the patch on customer setup directly without merge to upstream (patch the changes on customer test environment)
3. Recommendation to customer on these steps from RH end.