That was an issue in our testing cloud with their Ceph cluster. Now writing works well:

$ oc exec -ti new-nfs-share-pod bash
root@new-nfs-share-pod:/# mount | grep nfs4
172.16.32.1:/volumes/_nogroup/6241164b-4ab0-4358-ad50-1d3a3146cd23 on /var/lib/www type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.128.2.92,local_lock=none,addr=172.16.32.1)
root@new-nfs-share-pod:/# cd /var/lib/www/
root@new-nfs-share-pod:/var/lib/www# echo "Hello Manila!" > hello
root@new-nfs-share-pod:/var/lib/www# cat hello 
Hello Manila!

For this reason I close this bug.

Hi Mike,

I re-test it today(20200602), deployment with RWX still doesn't work.
There are 3 deployments using the same yaml file, and the difference are:
case 1. Manila with RWX: from the user and dir access mode, it could not write.
case 2. Cinder with RWO: ok
case 3. Manila with RWO: ok

Please see the following output, I also attach my yaml file:


[wduan@MINT 01_general]$ oc get pod,pvc
NAME                                      READY   STATUS    RESTARTS   AGE
pod/mydeploy01-5d87c8668-wgzqh            1/1     Running   0          87m
pod/mydeploy02-6f777c58c9-jmdfd           1/1     Running   0          48m
pod/mydeploy03-84898b8d66-s7gns           1/1     Running   0          6m18s

NAME                                STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS      AGE
persistentvolumeclaim/mydep-pvc01   Bound    pvc-bf92b5fc-efd2-4b73-8277-1f8eb49346b0   3Gi        RWX            csi-manila-ceph   87m
persistentvolumeclaim/mydep-pvc02   Bound    pvc-24793ed6-6509-4575-ba62-dfbca9a46e37   3Gi        RWO            standard          48m
persistentvolumeclaim/mydep-pvc03   Bound    pvc-7c6fe557-c52e-4eaa-8b66-edd7d194abf1   3Gi        RWO            csi-manila-ceph   6m20s


Manila RWX:
[wduan@MINT 01_general]$ oc rsh mydeploy01-5d87c8668-wgzqh
sh-4.4$ mount | grep nfs
172.16.32.1:/volumes/_nogroup/08715905-5d01-4c57-b932-7903b21347c8 on /mnt/local type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.129.2.11,local_lock=none,addr=172.16.32.1)
sh-4.4$ whoami
1000590000
sh-4.4$ ls -l mnt/
total 1
drwxr-xr-x. 2 99 99 0 Jun  2 06:55 local
sh-4.4$ touch /mnt/local/test
touch: cannot touch '/mnt/local/test': Permission denied



Cinder RWO:
[wduan@MINT 01_general]$ oc rsh mydeploy02-6f777c58c9-jmdfd 
sh-4.4$ whoami 
1000590000
sh-4.4$ ls -l mnt/
total 4
drwxrwsr-x. 3 root 1000590000 4096 Jun  2 07:34 local
sh-4.4$ touch /mnt/local/test
sh-4.4$ exit

Manila RWO:
[wduan@MINT 01_general]$ oc rsh mydeploy03-84898b8d66-s7gns
sh-4.4$ whoami
1000590000
sh-4.4$ ls -l /mnt       
total 1
drwxrwsr-x. 2 99 1000590000 0 Jun  2 08:16 local
sh-4.4$ touch /mnt/local/test
sh-4.4$ ls /mnt/local/test
/mnt/local/test


Yaml file:
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mydeploy01
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello-openshift
  template:
    metadata:
      labels:
        app: hello-openshift
    spec:
      containers:
      - name: hello-openshift
        image: docker.io/aosqe/storage@sha256:a05b96d373be86f46e76817487027a7f5b8b5f87c0ac18a246b018df11529b40
        ports:
        - containerPort: 80
        volumeMounts:
        - name: local
          mountPath: /mnt/local
      volumes:
      - name: local
        persistentVolumeClaim:
          claimName: mydep-pvc01

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mydep-pvc01
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 3G
  storageClassName: csi-manila-ceph

Verified pass on 4.6.0-0.nightly-2020-07-07-233934

[wduan@MINT manila]$ oc rsh dpod-6wmr5 
sh-4.4$ mount | grep nfs
172.16.32.1:/volumes/_nogroup/a27a8b70-de7f-4a72-bec1-5a7593c91749 on /mnt/storage type nfs4 (rw,relatime,vers=4.1,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.131.0.19,local_lock=none,addr=172.16.32.1)

sh-4.4$ whoami
1000590000

sh-4.4$ ls -l /mnt
total 1
drwxrwxrwx. 2 99 99 0 Jun 22 08:00 storage

sh-4.4$ cp /etc/hosts /mnt/storage 
sh-4.4$ touch /mnt/storage/test
sh-4.4$ ls /mnt/storage
hosts  test

Tested with deployment and daemonset:
[wduan@MINT manila]$ oc get all
NAME                              READY   STATUS    RESTARTS   AGE
pod/dpod-6wmr5                    1/1     Running   0          7m28s
pod/dpod-pxkst                    1/1     Running   0          7m28s
pod/dpod-x6fvm                    1/1     Running   0          7m27s
pod/mydeploy02-6f777c58c9-gfchh   1/1     Running   0          10m

NAME                  DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
daemonset.apps/dpod   3         3         3       3            3           <none>          7m31s

NAME                         READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/mydeploy02   1/1     1            1           23m

NAME                                    DESIRED   CURRENT   READY   AGE
replicaset.apps/mydeploy02-6f777c58c9   1         1         1       23m
[wduan@MINT manila]$ oc get pvc
NAME          STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS      AGE
mydep-pvc02   Bound    pvc-ab85e46a-4552-47c0-a421-bf8226b3d357   3Gi        RWX            csi-manila-ceph   24m
mypvc-rwx     Bound    pvc-4f378cab-14ae-465b-bbc4-d0670f46f0e9   2Gi        RWX            csi-manila-ceph   8m22s
[wduan@MINT manila]$

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (OpenShift Container Platform 4.6 GA Images), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:4196