To properly disable the idmapping option as commented in the documentation url [1] we need to disable the parameter in the client and server but the option shared is the doc is only for the server:

~~~
# echo 'Y' > /sys/module/nfsd/parameters/nfs4_disable_idmapping
~~~

As per other links like this one [2] to disable the client we need to do:

~~~
 # echo 'Y' > /sys/module/nfs/parameters/nfs4_disable_idmapping 
~~~

Which is similar but not equal. Also it is assumed with this statement that the server is the NFS server provider by a linux kernel which may not be the case.

Also it would be helpful to indicate that this change is not persistent and to make it persistent a machine config is needed to add this parameter to the kernel (for the client):

~~~
nfs.nfs4_disable_idmapping=1
~~~

An example (not verified) of a machine config for this purpose:
~~~
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 10-worker-kernelarg-disable-idmapping
spec:
  kernelArguments:
    - nfs.nfs4_disable_idmapping=1
~~~

[1] https://docs.openshift.com/container-platform/4.10/storage/persistent_storage/persistent-storage-nfs.html#additional-configuration-and-troubleshooting
[2] https://access.redhat.com/solutions/33455  (Disabling idmapping section)

Documentation from 4.10 to 4.13

NA

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