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 dev preview behind tech preview no upgrade feature gate. Feature is currently alpha in 1.33 (from a timeline pov it's not k8s aligned as it's out of tree)

Requirements (aka. Acceptance Criteria):

Ship the necessary side cars, enable feature gate and add the relevant CRDs

Use Cases (Optional):

As a driver/storage vendor I would like to start implementing / testing my driver with CBT with OCP

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

Questions to Answer (Optional):

Which driver should we test this with? Hostpath?

Out of Scope

Implementing / Testing /support a specific driver with CBT

Dev 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

DP likely a KCS + relnotes

Interoperability Considerations

Not environment specific