Kubernetes NFS Persistent Volume Mount Issues
If you are running Kubernetes on prem either with bare metal hardware or using your virtual machine infrastructure you will need to worry about other underlying packages that Kubernetes depends on for certain things. File system libraries are an example of something that could trip you up when using NFS. Assuming your PV and PVC are setup correctly to use an NFS share for your pods and when deploying you notice your pods wont start this may be your issue.
An example below if we describe our pv
$ kubectl describe pv <Persistent Volume>
~ Output Truncated ~
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 4m41s default-scheduler Successfully assigned default/nginx-95975fff6-6r97b to dlp-kube-01.corp.capitalcu.com
Warning FailedMount 2m38s kubelet Unable to attach or mount volumes: unmounted volumes=[nfs-share], unattached volumes=[kube-api-access-wsf5q nginx-secret nfs-share]: timed out waiting for the condition
Warning FailedMount 31s (x10 over 4m41s) kubelet MountVolume.SetUp failed for volume "testpv" : mount failed: exit status 32
Mounting command: mount
Mounting arguments: -t nfs 10.204.255.47:/var/nfs/general/ /var/snap/microk8s/common/var/lib/kubelet/pods/0c3c0a5c-1252-47d4-a164-3421465c5ab8/volumes/kubernetes.io~nfs/testpv
Output: mount: /var/snap/microk8s/common/var/lib/kubelet/pods/0c3c0a5c-1252-47d4-a164-3421465c5ab8/volumes/kubernetes.io~nfs/testpv: bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program.
Warning FailedMount 22s kubelet Unable to attach or mount volumes: unmounted volumes=[nfs-share], unattached volumes=[nfs-share kube-api-access-wsf5q nginx-secret]: timed out waiting for the condition
The key point here is on the second to last line where it says
bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount.<type> helper program. This is pointing that the underlying OS does not have the proper bineries to mount NFS.
All we need to do here is install the NFS binaries in order to properly mount it.
$ sudo apt-get install -y nfs-common
And after that you should be good to go.