How to find the maximum number of unique volumes managed by the CSI driver that can be used on a node

Solution Verified - Updated -

Environment

  • Red Hat OpenShift Container Platform 4.x.

Issue

  • Some CSI drivers set a maximum number of unique volumes managed by the CSI driver that can be used on a node and, when it is reached in all the nodes of the cluster, an event like this one shows up:
Warning  FailedScheduling        <unknown>  default-scheduler         0/2 nodes are available: 2 node(s) exceed max volume count
  • This situation implies that no pod using that CSI driver can be scheduled.

Resolution

$ oc get csinode -o yaml <node_name>
[...]
spec:
  drivers:
  - allocatable:
      count: 20
    name: com.mapr.csi-kdf
    nodeID: mynode.mydomain.org
    topologyKeys: null
  - allocatable:
      count: 20
    name: com.mapr.csi-nfskdf
    nodeID: mynode.mydomain.org
    topologyKeys: null
  - name: openshift-storage.cephfs.csi.ceph.com
    nodeID: mynode.mydomain.org
    topologyKeys: null
  - name: openshift-storage.rbd.csi.ceph.com
    nodeID: mynode.mydomain.org
    topologyKeys: null
  • The way to reconfigure this value depends on the provider of the CSI driver.
    • In the case of Red Hat OpenShift Data Foundation, there is no maximum set by default.
    • For other drivers or platforms, if any clarification is needed in this regard, the entity which supports them has to be contacted.

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