我在Ubuntu机器上安装了Kubernetes安装程序，我正在尝试安装一个nfs卷，并根据http://kubernetes.io/v1.1/examples/nfs/文档将其挂载到容器中。
nfs服务和pod配置

kind: Service
apiVersion: v1
metadata:
  name: nfs-server
spec:
  ports:
    - port: 2049
  selector:
    role: nfs-server
---
apiVersion: v1
kind: Pod
metadata:
  name: nfs-server
  labels:
    role: nfs-server
spec:
  containers:
    - name: nfs-server
      image: jsafrane/nfs-data
      ports:
        - name: nfs
          containerPort: 2049
      securityContext:
        privileged: true

pod配置以安装nfs卷

apiVersion: v1
kind: Pod
metadata:
  name: nfs-web
spec:
  containers:
    - name: web
      image: nginx
      ports:
        - name: web
          containerPort: 80
      volumeMounts:
          # name must match the volume name below
          - name: nfs
            mountPath: "/usr/share/nginx/html"
  volumes:
    - name: nfs
      nfs:
        # FIXME: use the right hostname
        server: 192.168.3.201
        path: "/"

当我运行kubectl describe nfs-web的时候，我得到了下面的输出，提到它无法挂载nfs卷。这可能是什么原因？

Name:               nfs-web
Namespace:          default
Image(s):           nginx
Node:               192.168.1.114/192.168.1.114
Start Time:         Sun, 06 Dec 2015 08:31:06 +0530
Labels:             <none>
Status:             Pending
Reason:             
Message:            
IP:             
Replication Controllers:    <none>
Containers:
  web:
    Container ID:   
    Image:      nginx
    Image ID:       
    State:      Waiting
      Reason:       ContainerCreating
    Ready:      False
    Restart Count:  0
    Environment Variables:
Conditions:
  Type      Status
  Ready     False 
Volumes:
  nfs:
    Type:   NFS (an NFS mount that lasts the lifetime of a pod)
    Server: 192.168.3.201
    Path:   /
    ReadOnly:   false
  default-token-nh698:
    Type:   Secret (a secret that should populate this volume)
    SecretName: default-token-nh698
Events:
  FirstSeen LastSeen    Count   From            SubobjectPath   Reason      Message
  ───────── ────────    ─────   ────            ─────────────   ──────      ───────
  36s       36s     1   {scheduler }                Scheduled   Successfully assigned nfs-web to 192.168.1.114
  36s       2s      5   {kubelet 192.168.1.114}         FailedMount Unable to mount volumes for pod "nfs-web_default": exit status 32
  36s       2s      5   {kubelet 192.168.1.114}         FailedSync  Error syncing pod, skipping: exit status 32