title: csi-cephfs: how can I get ceph storage cluster available capacity from kubernetes
body: <ol>
  <li><p>My goal is to get the capacity of ceph cluster by ceph-csi in kubernetes</p>
  </li>
  <li><p>Same as the command in ceph 'ceph -s'
  usage: 10 Gib used, 12GiB /22 GiB avail</p>
  </li>
  <li><p>Version is</p>
  <pre><code> ceph-csi v3.6.0
  
   kubernetes v1.21.8
  </code></pre>
  </li>
  <li><p>I already hava open the kubernetes feature gate CSIVolumeHealth,but in prometheus I did not find any useful info,only kubelet_volume_stats_*,but that all about persistenceVolume,not ceph cluster capacity.</p>
  </li>
  </ol>
  <p>anyone can help? plz</p>