How to change the hostname of a Linux system
Permanent hostname change on Debian based systems
Debian based systems use the file /etc/hostname to read the hostname of the system at boot time and set it up using the init script /etc/init.d/hostname.sh
/etc/hostname server
So on a Debian based system we can edit the file /etc/hostname and change the name of the system and then run:
/etc/init.d/hostname.sh start
to make the change active. The hostname saved in this file (/etc/hostname) will be preserved on system reboot (and will be set using the same script we used hostname.sh).
Permanent hostname change on RedHat based systems
RedHat based system use the file /etc/sysconfig/network to read the saved hostname at system boot. This is set using the init script /etc/rc.d/rc.sysinit
# vi /etc/sysconfig/network
NETWORKING="yes"
NETWORKING_IPV6="no"
HOSTNAME="your.homain.com"
GATEWAY="109.123.122.1"
So in order to preserve your change on system reboot edit this file and enter the appropriate name using the HOSTNAME variable.
Use sysctl to change the hostname
Why would someone need a different method of doing the same thing as above? No idea, but here is anyway: use sysctl to change the variable kernel.hostname:
Use:
sysctl kernel.hostname
to read the current hostname, and
sysctl kernel.hostname=NEW_HOSTNAME
to change it.
