kubelet mount error

kubelet.log

E0527 20:38:36.467942   11142 mount_linux.go:103] Mount failed: exit status 32
Mounting arguments: nfs-server.c.core-depth-94916.internal.:/ /var/lib/kubelet/pods/baa7584d-04a8-11e5-a27a-42010af022f2/volumes/kubernetes.io~nfs/nfs nfs []
Output: mount: wrong fs type, bad option, bad superblock on nfs-server.c.core-depth-94916.internal.:/,
       missing codepage or helper program, or other error
       (for several filesystems (e.g. nfs, cifs) you might
       need a /sbin/mount.<type> helper program)
       In some cases useful info is found in syslog - try
       dmesg | tail  or so