The remainder of this document assumes you have an NFSv4 server with the proper Kerberos principals for it and as well the principals for the NFSv4 client you are currently configuring. For information on creating these, see Doug Potter's Kerberos HOWTO.
To add the principals for your host to it's keytab, you can run these commands from a shell prompt (assuming you know the admin password for your Kerberos server):
kinit root/admin@MYDEPT.EXAMPLE.COM kadmin -r MYDEPT.EXAMPLE.COM kadmin: ktadd host/myhost.mydept.example.com@MYDEPT.EXAMPLE.COM kadmin: ktadd nfs/myhost.mydept.example.com@MYDEPT.EXAMPLE.COM kadmin: quit