RHEL6.3 and newer NFS clients and servers disable idmapping when utilizing the AUTH_SYS/UNIX authentication flavor by enabling the following booleans:
NFS
client
#
echo 'Y' > /sys/module/nfs/parameters/nfs4_disable_idmapping
NFS server
# echo 'Y'
> /sys/module/nfsd/parameters/nfs4_disable_idmapping
