Creating Block volume Failed with default block storage class

Issue

• Can no longer take gluster block storage e.g for Prometheus/Alertmanager in 3.11.51:

# oc get events -n openshift-monitoring | grep Volume13m         1h           104       prometheus-k8s-db-prometheus-k8s-0.15720af890eb3511             PersistentVolumeClaim                                                  Warning   ProvisioningFailed     gluster.org/glusterblock 49887ae5-0453-11e9-b28f-0a580a820202   Failed to provision volume with StorageClass "glusterfs-storage-block": failed to create volume: heketi block volume creation failed: [heketi] failed to create volume: server did not provide a message (status 500: Internal Server Error)3m          1h           8398      prometheus-k8s-0.15720af3e28ef736                               Pod                                                                    Warning   FailedScheduling       default-scheduler                                               pod has unbound PersistentVolumeClaims (repeated 3 times)3m          1h           2039      prometheus-k8s-db-prometheus-k8s-0.15720af3e284f9a5             PersistentVolumeClaim                                                  Normal    ExternalProvisioning   persistentvolume-controller                                     waiting for a volume to be created, either by external provisioner "gluster.org/glusterblock" or manually created by system administrator3m          1h           125       prometheus-k8s-db-prometheus-k8s-0.15720af3e4ed6d5e             PersistentVolumeClaim                                                  Normal    Provisioning           gluster.org/glusterblock 49887ae5-0453-11e9-b28f-0a580a820202   External provisioner is provisioning volume for claim "openshift-monitoring/prometheus-k8s-db-prometheus-k8s-0"

# oc get pvc -n openshift-monitoring
NAME                                 STATUS    VOLUME    CAPACITY   ACCESS MODES   STORAGECLASS              AGE
prometheus-k8s-db-prometheus-k8s-0   Pending                                       glusterfs-storage-block   1h