After configuring NSS mirroring and creating a volume on the mirrored NSS partition and pool, if you did not cluster-enable the NSS pool on the mirrored partition when you created it, do so by following the instructions in Cluster-Enabling an Existing NSS Pool and Its Volumes in the OES 2018 SP3: OES Cluster Services for Linux Administration Guide.
When you cluster-enable a shared disk pool, the commands to start and stop the pool resource are automatically added to the resource load and unload scripts.