I am deploying Elasticsearch cluster on Kubernetes in AWS EKS. The spec I have is:

apiVersion: elasticsearch.k8s.elastic.co/v1
kind: Elasticsearch
metadata:
  name: es
spec:
  version: 7.14.0
  nodeSets:
  - name: node
    count: 2
    config:
      node.store.allow_mmap: false
    volumeClaimTemplates:
    - metadata:
        name: elasticsearch-data
      spec:
        accessModes:
          - ReadWriteOnce
        storageClassName: ebs-sc
        resources:
          requests:
            storage: 1024Gi

When I deploy I got this error:

for: "es.yml": admission webhook "elastic-es-validation-v1.k8s.elastic.co" denied the request: Elasticsearch.elasticsearch.k8s.elastic.co "es" is invalid: spec.nodeSet[0].volumeClaimTemplates: Invalid value: []v1.PersistentVolumeClaim{v1.PersistentVolumeClaim{TypeMeta:v1.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:v1.ObjectMeta{Name:"elasticsearch-data", GenerateName:"", Namespace:"", SelfLink:"", UID:"", ResourceVersion:"", Generation:0, CreationTimestamp:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), DeletionTimestamp:<nil>, DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil), OwnerReferences:[]v1.OwnerReference(nil), Finalizers:[]string(nil), ClusterName:"", ManagedFields:[]v1.ManagedFieldsEntry(nil)}, Spec:v1.PersistentVolumeClaimSpec{AccessModes:[]v1.PersistentVolumeAccessMode{"ReadWriteOnce"}, Selector:(*v1.LabelSelector)(nil), Resources:v1.ResourceRequirements{Limits:v1.ResourceList(nil), Requests:v1.ResourceList{"storage":resource.Quantity{i:resource.int64Amount{value:1099511627776, scale:0}, d:resource.infDecAmount{Dec:(*inf.Dec)(nil)}, s:"", Format:"BinarySI"}}}, VolumeName:"", StorageClassName:(*string)(0xc000cd2600), VolumeMode:(*v1.PersistentVolumeMode)(nil), DataSource:(*v1.TypedLocalObjectReference)(nil)}, Status:v1.PersistentVolumeClaimStatus{Phase:"", AccessModes:[]v1.PersistentVolumeAccessMode(nil), Capacity:v1.ResourceList(nil), Conditions:[]v1.PersistentVolumeClaimCondition(nil)}}}: volume claim templates can only have their storage requests increased, if the storage class allows volume expansion. Any other change is forbidden

The spec includes volumeClaimTemplates which is used to claim the persistent storage. I don't understand why it says volume claim templates can only have their storage requests increased, if the storage class allows volume expansion.

I have checked PVC is empty:

$ kubectl get pvc
No resources found in default namespace.

And I have below spec for storage class:

kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: ebs-sc
provisioner: ebs.csi.aws.com
allowVolumeExpansion: true
volumeBindingMode: WaitForFirstConsumer