Kubernetes Persistent Volume incorrect size (3.0Gb vs 15Gi)

Docker Desktop
1

I am running Kubernetes in Docker for Desktop on Mac (v 2.3.0.3 (45519) with Kubernetes v1.16.5).

I have declared a Persistent Volume with a size of 15Gi, but the volume itself when mounted is only 3Gb. Docker is showing that I have only used 25 GB of my allocated 60 GB of storage, so it’s not running out of drive space.

Where is this 3.0GB volume size definition coming from? And how can I make it match what I requested in the PV?

Thanks!

PV & PVC:

---
kind: PersistentVolume
apiVersion: v1
metadata:
  name: backend-pv-volume
  namespace: coding-dev
  labels:
    type: local
    app: backend
spec:
  storageClassName: manual
  capacity:
    storage: 15Gi
  accessModes:
    - ReadWriteMany
  hostPath:
    path: "/mnt/coding-data-dev"

---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: backend-pv-claim
  namespace: coding-dev
  labels:
    app: backend
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 15Gi

Pod (for testing):

---
apiVersion: v1
kind: Pod
metadata:
  name: load-data-pod
  namespace: coding-dev
spec:
  containers:
    - name: load-data-pod
      image: pgardella/awscli
      command: ["/bin/sh", "-c", "--"]
      args: [ "while true; do sleep 30; done;" ]
      volumeMounts:
      - mountPath: /app/data
        name: data-dir
  restartPolicy: Never
  volumes:
  - name: data-dir
    persistentVolumeClaim:
      claimName: backend-pv-claim

Inside the Pod:

root@load-data-pod:/# df -h
Filesystem      Size  Used Avail Use% Mounted on
overlay          59G   25G   31G  45% /
tmpfs            64M     0   64M   0% /dev
tmpfs           3.0G     0  3.0G   0% /sys/fs/cgroup
/dev/vda1        59G   25G   31G  45% /etc/hosts
overlay         3.0G  3.0G     0 100% /app/data
shm              64M     0   64M   0% /dev/shm
tmpfs           3.0G   12K  3.0G   1% /run/secrets/kubernetes.io/serviceaccount
tmpfs           3.0G     0  3.0G   0% /proc/acpi
tmpfs           3.0G     0  3.0G   0% /sys/firmware