Is your feature request related to a problem? Please describe (👍 if you like this request)

To current design, when node controller decide to delete a backing image copy from a disk, there is not corresponding logs for the reason of deletion. When it wrongly deletes a copy, the BI spec is already updated and there is nothing to trace the deleted copy.

Describe the solution you'd like

Node controller need to at lease write the log down the detail of the decision of image copy deletion.

• What is the required minimum number of retained copies?
• How many copies are there before or after this deletion?
• How many failed copies are counted at this moment?
• What is the state of this deleting copy?

These information helps us to track the image copy history.

Describe alternatives you've considered

BI controller passively handles the copy deletion event with the BI CR spec change. Only the Node controller knows the reason of the spec change.

In the other hand, to current design, we don't have dedicate CR to track state of BI copies. All the events are recorded in BI scope, not for an individual copy.

Additional context

No response