To change your server’s hostname manually on CentOS / RHEL is quite easy. Simply edit the file /etc/sysconfig/network with your favorite text editor and change the value of the HOSTNAME parameter to the new hostname. Your configuration file should look something like this:
/etc/sysconfig/network
NETWORKING=yes
HOSTNAME=”newhostname.domainname.com”
GATEWAY=”192.168.0.1″GATEWAYDEV=”eth0″
FORWARD_IPV4=”yes”
You’ll also need to replace all occurencies of your old hostname in /etc/hosts. [...]

When you’re working remotely on a Linux server through SSH, you are at risk of losing important data if you encounter a network failure. Worst than that, you could even end up “breaking” your Linux box or locking yourself out. Think about a critical component installation interrupted by a network problem. That could mean disaster [...]

Sometimes your web server’s internal clock can be somewhat unreliable. While this may not have any considerable consequences on an isolated server or network, this can turn out to be a nightmare when you connect it to the Internet.