I will be running a pod with persistent SSD. I already have the disk ready (created from snapshot) I want to attach this disk to a pod. So far, I have been creating the pod in this manner

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: geth-stateful
  namespace: dev
spec:
  serviceName: geth-dev-service
  replicas: 2
  selector:
    matchLabels:
      app: geth-node
  template:
    metadata:
      labels:
        app: geth-node
    spec:
      containers:
      - name: geth-node
        image: asia.gcr.io/indiesquare-dev/geth-node:v1.8.12
        ports:
        volumeMounts:
        - name: geth-chaindata
          mountPath: /var/tmp
        resources:
          requests:
            memory: "13Gi"
            cpu: "5000m"
          limits:
            memory: "14Gi"
            cpu: "5500m"   
  volumeClaimTemplates:
  - metadata:
      name: geth-chaindata
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: fast
      resources:
        requests:
          storage: 500Gi

However, this always creates a new disk. Is there a way to provide an already existing disk as volumeMounts?