NFS pod creation failed

Hi,

Regarding the new deployments of PVC at Lab 8.3 step 6, for some reason it failed because of "FailedMount" from "kubectl describe pod - " result.

Here is the part of the output:

Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 22m default-scheduler Successfully assigned default/nginx-nfs-5486786d68-npgvf to ip-172-31-11-107
Warning FailedMount 6m47s (x3 over 11m) kubelet Unable to attach or mount volumes: unmounted volumes=[nfs-vol], unattached volumes=[kube-api-access-zbzjv nfs-vol] : timed out waiting for the condition
Warning FailedMount 2m11s (x6 over 20m) kubelet Unable to attach or mount volumes: unmounted volumes=[nfs-vol], unattached volumes=[nfs-vol kube-api-access-zbzjv] : timed out waiting for the condition
Warning FailedMount 89s (x9 over 20m) kubelet MountVolume.SetUp failed for volume "pvvol-1" : mount failed: exit status 32
Mounting command: mount
Mounting arguments: -t nfs cp:/opt/sfw /var/lib/kubelet/pods/e30a0f9a-6cb0-45fa-9f02-e268a5f299d5/volumes/kubernetes.io~nfs/pvvol-1
Output: mount.nfs: Connection timed out

I think both pv and pvc configuration are OK:

ubuntu@ip-172-31-5-226:~$ kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvvol-1 1Gi RWX Retain Bound default/pvc-one 82m

ubuntu@ip-172-31-5-226:~$ kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
pvc-one Bound pvvol-1 1Gi RWX 80m

And also nfs-common installation at worker node side is OK.

What is the main cause of this "failed mount" problem?