In Deployment files from GKE, you need to change spec.volumes settings according to your Persistent Volume setups.

I recommend you to choose one of the following options:

1. The easiest way is to use HostPath. It mounts a file or a directory from the host Node’s file system into your Pod. Note that in this case, data on one Node is not reachable from another Node without additional configurations. Example of usage in Kubernetes:

   apiVersion: v1
   kind: Pod
   metadata:
     name: test-pd
   spec:
     containers:
     - image: k8s.gcr.io/test-webserver
       name: test-container
       volumeMounts:
       - mountPath: /test-pd
         name: test-volume
     volumes:
     - name: test-volume
       hostPath:
         # directory location on host
         path: /data
         # this field is optional
         type: Directory

2. You can use NFS. You need to configure NFS server and after that you can use its volumes in Deployments via Persistent Volume Claims. Example of usage in Kubernetes:

   apiVersion: v1
   kind: Deployment
   metadata:
     name: nfs-busybox
   spec:
     replicas: 2
     selector:
       name: nfs-busybox
     template:
       metadata:
         labels:
           name: nfs-busybox
       spec:
         containers:
        - image: busybox
           command:
             - sh
             - -c
             - 'while true; do date > /mnt/index.html; hostname >> /mnt/index.html; sleep $(($RANDOM % 5 + 5)); done'
           imagePullPolicy: IfNotPresent
           name: busybox
           volumeMounts:
             # name must match the volume name below
             - name: nfs
               mountPath: "/mnt"
         volumes:
         - name: nfs
           persistentVolumeClaim:
             claimName: nfs

   You can look through the link for more information about using NFS.

3. You can use GlusterFS. You need to configure your own GlusterFS installation, and after that you can use its volumes in Deployments. Example of usage in Kubernetes:

   apiVersion: v1
   kind: Deployment
   metadata:
     name: nfs-busybox
   spec:
     replicas: 2
     selector:
       name: nfs-busybox
     template:
       metadata:
         labels:
           name: nfs-busybox
       spec:
         containers:
        - image: busybox
           command:
             - sh
             - -c
             - 'while true; do date > /mnt/index.html; hostname >> /mnt/index.html; sleep $(($RANDOM % 5 + 5)); done'
           imagePullPolicy: IfNotPresent
           name: busybox
           volumeMounts:
             # name must match the volume name below
             - name: nfs
               mountPath: "/mnt"
         volumes:
         - name: glusterfsvol
           glusterfs:
             endpoints: glusterfs-cluster
               path: kube_vol
               readOnly: true

   You can look through the link for more information about using GlusterFS.

You can find more information about Persistent Volumes and Persistent Volume Claims here.