<p>I've successfully deployed a Kubernetes cluster using the <a href="https://github.com/kubernetes/kube-deploy" rel="nofollow noreferrer">docker-multinode configuration</a> as well as a Ceph cluster and am able to mount a CephFS device manually using the following:</p>

<p><code>sudo mount -t ceph monitor1:6789:/ /ceph -o name=admin,secretfile=/etc/ceph/cephfs.secret</code></p>

<p>I'm now attempting to launch a pod using the kubernetes example <a href="https://github.com/kubernetes/kubernetes/tree/master/examples/volumes/cephfs" rel="nofollow noreferrer">here</a>:</p>

<pre><code>apiVersion: v1
kind: Secret
metadata:
  name: ceph-secret
data:
  key: my-ceph-secret-key
---
apiVersion: v1
kind: Pod
metadata:
  name: cephfs2
spec:
  containers:
  - name: cephfs-rw
    image: kubernetes/pause
    volumeMounts:
    - mountPath: "/mnt/cephfs"
      name: cephfs
  volumes:
  - name: cephfs
    cephfs:
      monitors:
      - "monitor1:6789"
      - "monitor2:6789"
      - "monitor3:6789"
      user: admin
      secretRef:
        name: ceph-secret
      readOnly: false
</code></pre>

<p>When I run:</p>

<p><code>sudo kubectl create -f cephfs.yml</code></p>

<p>I am receiving the following error:</p>

<blockquote>
  <p>Warning       FailedMount MountVolume.SetUp failed for volume
  "kubernetes.io/cephfs/445ee063-d1f1-11e6-a3e3-1418776a29a6-cephfs"
  (spec.Name: "cephfs") pod "445ee063-d1f1-11e6-a3e3-1418776a29a6" (UID:
  "445ee063-d1f1-11e6-a3e3-1418776a29a6") with: CephFS: mount failed:
  mount failed: fork/exec /bin/mount: invalid argument Mounting
  arguments: monitor1:6789,monitor2:6789,monitor3:6789:/data
  /var/lib/kubelet/pods/445ee063-d1f1-11e6-a3e3-1418776a29a6/volumes/kubernetes.io~cephfs/cephfs
  ceph [name=admin,secret=secret]</p>
</blockquote>

<p>Do the kubernetes manager containers need to have the ceph-fs-common package installed in order to perform a successful mount?  I cannot find any further debugging information to determine the cause of the error.</p>

<p>AFAIK you might have 2 problems here:</p>

<ul>
<li>Ceph required the ip addresses of the machines to work</li>
<li>The OS you are running the container on, is the one which mounts the storage: The ceph tooling needs to be installed on that machine. The container is completely unaware of the mounted disks</li>
</ul>
