Upgrade your running Linux to SL 6.3 headless and medialess

Installing new running linux without  going in to cluster room:)
Without PXE and CD/DVD or USB.

On the host with old linux.
cd /boot

curl http://ftp1.scientificlinux.org/linux/scientific/6.3/x86_64/os/images/pxeboot/vmlinuz -o vmlinuz-sl63
curl http://ftp1.scientificlinux.org/linux/scientific/6.3/x86_64/os/images/pxeboot/initrd.img -o initrd-sl63

update Grub:
Add following:

title Remote SL63 OS Install
   root (hd0,0)
   kernel /vmlinuz-sl63 vnc vncconnect=n.n.n.n headless ip=n.n.n.n
     netmask=n.n.n.n gateway=n.n.n.n dns=n.n.n.n hostname=x ksdevice=eth0
     method=http://ftp1.scientificlinux.org/linux/scientific/6.3/x86_64/os lang=en_US keymap=us
   initrd /initrd-sl63.img

If your remote machine does not use a static IP address but uses DHCP instead, the recipe is a little different. In the case of DHCP you can leave off the netmask, gateway, and dns parameters and just replace "ip=n.n.n.n" with "ip=dhcp".

The full list of parameters:

vnc
vncconnect={IP address of machine where you will run vncviewer in listen mode}
headless
ip={IP address for the remote machine}
netmask={netmask for the remote machine}
gateway={gateway IP address for the remote machine}
dns={IP address for the DNS server}
hostname={desired FQDN}
ksdevice={name of network device}
method={URL to parent directory of images/state2.img}
lang={proper language code}
keymap={proper country code}