How to use Changed Block Tracking (Dev Preview) in OpenShift 4.20

Issue

OCP 4.20 introduces changed block tracking as a Developer Preview feature. Changed block tracking enables efficient and incremental backups and disaster recovery for persistent volumes (PVs) managed by Container Storage Interface (CSI) drivers. It allows consumers to requests a list of blocks that have changed between two snapshots, which is useful for backup solutions vendors. By only backing up changed blocks, rather than entire volumes, back up processes are more efficient. This KCS demonstrates how developers can begin testing this feature with CSI drivers that support it.

Important: Changed block tracking is a Developer Preview feature only. Developer Preview features are not supported by Red Hat in any way and are not functionally complete or production-ready. Refer to Developer Preview - Scope of Support for more information.