Migration of volume replicas from one pool to another pool

Description:
I have cstorpoolcluster(CSPC) resource created on top of 3 nodes(That interns creates CSPI resources) and I deployed CSI-Volumes on top of above CSPC.

Now My Setup looks like:

kubectl get nodes
NAME                                        STATUS   ROLES    AGE    VERSION
gke-sai-test-cluster-pool-1-8d7defe8-37rr   Ready    <none>   102m   v1.14.8-gke.33
gke-sai-test-cluster-pool-1-8d7defe8-8471   Ready    <none>   102m   v1.14.8-gke.33
gke-sai-test-cluster-pool-1-8d7defe8-8nt0   Ready    <none>   102m   v1.14.8-gke.33
gke-sai-test-cluster-pool-1-8d7defe8-chws   Ready    <none>   102m   v1.14.8-gke.33

 kubectl get cspi -n openebs
NAME                     HOSTNAME                                    ALLOCATED   FREE    CAPACITY   STATUS   AGE
cstor-sparse-cspc-kdrs   gke-sai-test-cluster-pool-1-8d7defe8-8471   154K        9.94G   9.94G      ONLINE   13m
cstor-sparse-cspc-nb99   gke-sai-test-cluster-pool-1-8d7defe8-8nt0   158K        9.94G   9.94G      ONLINE   13m
cstor-sparse-cspc-twjx   gke-sai-test-cluster-pool-1-8d7defe8-chws   312K        9.94G   9.94G      ONLINE   13m

kubectl get cvr -n openebs
NAME                                                              USED   ALLOCATED   STATUS    AGE
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-kdrs   6K     6K          Healthy   105s
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-nb99   6K     6K          Healthy   105s
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-twjx   6K     6K          Healthy   105s

Now I performed horizontal scaleup of CSPC which created CSPI on new nodes

 kubectl get cspi -n openebs
NAME                     HOSTNAME                                    ALLOCATED   FREE    CAPACITY   STATUS   AGE
cstor-sparse-cspc-kdrs   gke-sai-test-cluster-pool-1-8d7defe8-8471   161K        9.94G   9.94G      ONLINE   15m
cstor-sparse-cspc-kmt7   gke-sai-test-cluster-pool-1-8d7defe8-37rr   50K         9.94G   9.94G      ONLINE   42s
cstor-sparse-cspc-nb99   gke-sai-test-cluster-pool-1-8d7defe8-8nt0   161K        9.94G   9.94G      ONLINE   15m
cstor-sparse-cspc-twjx   gke-sai-test-cluster-pool-1-8d7defe8-chws   161K        9.94G   9.94G      ONLINE   15m

Scenario:
I want to remove the node gke-sai-test-cluster-pool-1-8d7defe8-chws from my cluster. I performed horizontally scaled of the pool(i.e removed the pool spec of the above node from CSPC), but before scaling down the pool from that node I want to move volume replicas on that pool to the different pool(which was newly created i.e cstor-sparse-cspc-kmt7). How I can achieve that without many manual steps.

I want volume replicas on below pools

kubectl get cvr -n openebs
NAME                                                              USED   ALLOCATED   STATUS    AGE
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-kdrs   6K     6K          Healthy   105s
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-nb99   6K     6K          Healthy   105s
pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-kmt7   6K     6K          Healthy   105s

In above migrated the volume replica from pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-twjx to pvc-3f83cac1-5f80-11ea-85dd-42010a800121-cstor-sparse-cspc-kmt7

The issue names no source files or tests. Start with the CSPC scale-down workflow and the kubectl resources shown for CSPC, CSPI, and CVR, then determine how a replica can move from the removed pool to the new pool. Done means the replica is present on cstor-sparse-cspc-kmt7 and the original node can be removed without manual per-volume steps.