How to change the hostname in Linux

1. See hostname
   

   hostname
   

   OR

   sysctl kernel.hostname
   

2. Set the new hostname
   

   hostname NEW_HOSTNAME
   

   OR

   sysctl kernel.hostname=NEW_HOSTNAME
   

3. Permanent change
   • on Ubuntu and any others based on Debian
     

     vi /etc/hostname
     

     replace OLD_HOSTNAME with NEW_HOSTNAME

     service hostname start
     

   • on CentOS and any others based on Redhat
     

     vi /etc/sysconfig/network
     

     replace HOSTNAME="OLD_HOSTNAME" with NEW_HOSTNAME

     /etc/rc.d/rc.sysinit