SOLVED: nss_getpwnam errors in CentOS 6

I've been getting an annoying error in the system logs for newly installed CentOS 6 servers with NFS4 configured.  

rpc.idmapd[6004]: nss_getpwnam: name 'root@localdomain' does not map into domain 'mydomain.net'

This error doesn't appear to cause any issues but I don't like that sort of thing constantly spamming my logs so I wanted to fix it. So, it turns out that RHEL6/CentOS6 has a dodgy default configuration for the rpcidmapd service that you need to fix.

Edit this file:

 # vi /etc/idmapd.conf

Find the setting for "Domain" which is incorrectly set to an edu domain and change it so that it is like this:

 Domain = localdomain

Restart the service:

 # service rpcidmapd restart

After this you should no longer get the above error in your system log.