Desired Count is higher than Current Count for NDM in OpenShift 3.x

In OpenShift 3.x, NDM daemonset Desired Count is higher than Current Count.  This has been seen Kubernetes version below 1.12.  

Run below command to get the daemonset details of NDM.

kubectl get ds openebs-ndm -n <openebs-installed-namespace>

 Example output:

NAME        DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE 
openebs-ndm 4       3       3     3          3         <none>        7m6s

This is happening because DaemonSet Controller is responsible for scheduling the daemonset pods till the Kubernetes version 1.12. Daemonset controller tries to set the desired count to the number of nodes irrespective of checking whether the node is schedulable or not. This may happen due to the following cases:

• If any NodeSelector has been used to deploy openebs related pods.

• Master or any Node has been tainted in k8s cluster.

 By default, this kind of controller is disabled in k8s v1.12 and above. 

Note: If you are doing an upgrade of OpenEBS version when K8s version is below 1.12, then ensure to  make the NDM daemonset DESIRED count is equal to CURRENT count.