VolumeClaimTemplate:

volumeClaimTemplate:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 30Gi

Official example

https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#components

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx # has to match .spec.template.metadata.labels
  serviceName: "nginx"
  replicas: 3 # by default is 1
  minReadySeconds: 10 # by default is 0
  template:
    metadata:
      labels:
        app: nginx # has to match .spec.selector.matchLabels
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: registry.k8s.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "my-storage-class"
      resources:
        requests:
          storage: 1Gi

Elasticsearch helm chart templates/statefulset.yaml

   {{- if .Values.persistence.enabled }}
   volumeClaimTemplates:
   - metadata:
       name: {{ template "elasticsearch.uname" . }}
     {{- if .Values.persistence.labels.enabled }}
       labels:
         release: {{ .Release.Name | quote }}
         chart: "{{ .Chart.Name }}"
         app: "{{ template "elasticsearch.uname" . }}"
         {{- range $key, $value := .Values.labels }}
         {{ $key }}: {{ $value | quote }}
         {{- end }}
     {{- end }}
     {{- with .Values.persistence.annotations  }}
       annotations:
 {{ toYaml . | indent 8 }}
     {{- end }}
     spec:
 {{ toYaml .Values.volumeClaimTemplate | indent 6 }}
   {{- end }}

Related

labels:
kind: StatefulSet

See also

• Kubernetes storage, storage classes, PersistentVolume (PV), PVC, CSI, kind: StorageClass, kind: PersistentVolumeClaim, kind: PersistentVolume, kubectl [ get | describe | edit ] pvc, volumeClaimTemplates:, kubectl patch pv, FailedMount, Volume Expansion, Volume Cloning, snapshots, ExtraVolumes, NotTriggerScaleUp, volumePVCDataSource, AllowVolumeExpansion, EKS storage, provisioner, Storage Capacity Tracking, VolumeBinding, VolumeClaimTemplate, storage.k8s.io, CKA Storage, DoKC, emptyDir, Volume populators, storageclass.kubernetes.io, Rook, Longhorn, projected volumes