To rename a Linux box, e.g. from vinu to melanie

  vi /etc/hosts
and change the one line, e.g. from 10.224.88.51    vinu.delphion.com
                                to 10.224.88.51    melanie.delphion.com

  vi /etc/sysconfig/network
and change the one line, e.g. from HOSTNAME=vinu.delphion.com
                                to HOSTNAME=melanie.delphion.com

 ----------------------------------------------------------------------

And if you had registered the machine to the Red Hat Network (rhn) like
I had done for kristine, which I renamed to vinu, you need to also
  vi /etc/sysconfig/rhn/systemid
and change the one line,
e.g. from <value><string>kristine.delphion.com</string></value>
       to <value><string>vinu.delphion.com</string></value>

Then go onto the rhn web site, https://rhn.redhat.com
and delete this system's profile.

 ----------------------------------------------------------------------

Over on loon,
  vi /etc/named.data /etc/88.224.10.in-addr.arpa
and change the name server information.

Then
  refresh -s named

 ----------------------------------------------------------------------

Reboot your machine.  It should come up as the new name.

 ----------------------------------------------------------------------

If this is an officially-registered system, after the reboot, you'll
need to reregister with rhn.

  klog jasper  ('cause it wants to write into /afs/d/software/fixes ...)
  up2date --register

On the "Login" screen, 
  switch from "Create New Account" to "Use Existing Account"
  For "Username:", use rickjasper,
  For "Password:", use your standard Internet password.