Add NFS datastore using VMWare PowerCLI

To add a NFS datastore to a single VMHost:

Get-VMHost "HOSTNAME" | New-Datastore -Nfs -Name "DATASTORE_NAME" -Path "VOLUME_MOUNT_PATH" -NfsHost "IP_OR_HOSTNAME_OF_NFS_HOST"  

To add a NFS datastore to all VMHosts in a Cluster:

Get-Cluster "CLUSTERNAME" | Get-VMHost "HOSTNAME" | New-Datastore -Nfs -Name "DATASTORE_NAME" -Path "VOLUME_MOUNT_PATH" -NfsHost "IP_OR_HOSTNAME_OF_NFS_HOST"