Hi,

I have very basic two questions.

1.
[root@Root root]#
HOw can I change above prompt to [XYZ]#

2.
HOw can I know machine's host name? and HOw can I cahnge it?

1) To change the prompt type export PS1="[Whatever you want your prompt to be]"

2) Google search returned the following:

Edit the name in /etc/hosts

Edit /etc/sysconfig/network. It'll contain something like this:
NETWORKING=yes
HOSTNAME="yourserver.com"

Edit /etc/hostname. e.g. echo "yourserver.com" > /etc/hostname

Reboot your server, or just run: "hostname --file /etc/hostname" i.e. set the host name based on the name in the /etc/hostname file.

Applications that were running before you changed the hostname will probably not reflect the new host name until after an application (or server) restart.