Stuck at "Initializing Nextcloud..." when attached to NFS PVC

Doing my best to dupe helm/charts#22920 over to the new repo as I am experiencing this issue as well. I have refined the details a bit, as this issue appears to be specifically related to NFS-based storage.

Describe the bug

When bringing up the nextcloud pod via the helm chart, the logs show the pod as being stuck at:

2020-08-31T19:00:42.054297154Z Configuring Redis as session handler
2020-08-31T19:00:42.098305129Z Initializing nextcloud 19.0.1.1 ...

Even backing out the liveness/readiness probes to over 5 minutes does not give
If I instead switch the PVC to my storageClass for Rancher Longhorn (iSCSI) for example, the nextcloud install initializes in seconds.

Version of Helm and Kubernetes:

helm: v3.3.0
kubernetes: v1.18.6

Which chart:

nextcloud/helm

What happened:

• Namespace is created.
• Helm creates NFS PVC, or it is created manually
• Helm instantiates Nextcloud pod
• Nextcloud pod attaches PVC, and starts
• Nextcloud container is stuck at the above line

What you expected to happen:

Nextcloud finishes initialization
Nextcloud files appear with correct permissions on NFS volume

How to reproduce it (as minimally and precisely as possible):

Set up an NFS provisioner:

helm install stable/nfs-client-provisioner nfs  \
--set nfs.server=x.x.x.x --set nfs.path=<path>

OR
Configure an NFS PV and PVC manually

apiVersion: v1
kind: PersistentVolume
metadata:
  name: nextcloud-data
  labels:
    app: cloud
    type: data
spec:
  capacity:
    storage: 100Ti
  nfs:
    path: <path>
    server: <server>
  mountOptions:
    - async
    - nfsvers=4.2
    - noatime
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs-manual
  volumeMode: Filesystem
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: nextcloud-data
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100Ti
  storageClassName: nfs-manual
  volumeMode: Filesystem
  selector:
    matchLabels:
      app: cloud
      type: data

Install nextcloud
helm install -f values.yaml nextcloud/helm nextcloud --namespace=nextcloud

values.yaml:

image:
  repository: nextcloud
  tag: 19
readinessProbe:
  initialDelaySeconds: 560
livenessProbe:
  initialDelaySeconds: 560
resources:
  requests:
    cpu: 200m
    memory: 500Mi
  limits:
    cpu: 2
    memory: 1Gi
ingress:
  enabled: true
  annotations:
    cert-manager.io/cluster-issuer: acme
    kubernetes.io/ingress.class: nginx
    # nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
  hosts:
    - "cloud.myhost.com"
  tls:
    - hosts:
        - "cloud.myhost.com"
      secretName: prod-cert
  path: /
nextcloud:
  username: admin
  password: admin1
  # datadir: /mnt/data
  host: "cloud.myhost.com"
internalDatabase:
  enabled: true
externalDatabase:
  enabled: false
persistence:
  enabled: true
  # accessMode: ReadWriteMany
  # storageClass: nfs-client if creating via provisioner
  existingClaim: nextcloud-data # comment out if creating new PVC via provisioner