Quiesce point for PV - Elasticsearch

Project: RFE
Issue Type[s]: Features

1. Proposed title of this feature request:-

Quiesce point for PV for backup purpose

2. What is the nature and description of the request?

Establish quiesce point for PV before taking snapshot backup.
Customer currently does "--scale=0" for user application, which is not managed by Operator.
But for other components of Openshift: Image-Registry, Prometheus and Elasticsearch, there is no recommended way.

CU is interested in somewhat similar functionality: https://github.com/kubernetes/enhancements/blob/master/keps/sig-storage/20190120-execution-hook-design.md
And "how to configure ExecutionHook for ImageRegistry, ElasticSearch, Prometheus ?

3. Why does the customer need this? (List the business requirements here)

PV data may be corrupted if we didn't establish a quiesce point before taking a snapshot.

4. List any affected packages or components.

• Elasticsearch