Feature Overview (aka. Goal Summary)  

Changed block tracking allows consumers to requests a list of block that have changed between two snapshots which is an essential for some storage third party partners such as backup solutions vendors.

This feature is CSI driver dependent, providing this as early as possible is important to let both driver's and backup partners to start implementation / testing as soon as possible.

Goals (aka. expected user outcomes)

Ship CBT as tech preview behind tech preview no upgrade feature gate. Feature is currently DP since 4.20

Requirements (aka. Acceptance Criteria):

Wait for CBT to be graduated beta upstream.

Help with upstream activities

Pass e2e test with hostpath CSI (we can also collaborate with ODF for extended coverage)

Use Cases (Optional):

As a driver/storage vendor I would like to test my driver with CBT with OCP

As a backup vendore I would like to start implementing / testing my backup solution with CBT with OCP

As an OCP customer I want to start testing backup solution with CBT enabled

Out of Scope

Implementing / Testing /support a specific driver with CBT

Tech preview scope

Background

CBT is a critical feature for backups vendors as it improves / speed up the backup process for incremental or differentials backups.

Customer Considerations

No customer consideration for DP, they usually don't interfere with CBT directly. They will benefit it when driver / backups solution will leverage it.

Documentation Considerations

relnotes 

We need to discuss what kind of doc content we want to expose to customer since it's not supposed to be directly leveraged by customers.

Interoperability Considerations

Not environment specific, CSI driver has to be support it.