Changing hostname is not a usual task that we perform in our day today activity, however if somehow, we’ve to change the hostname, then we can do it using 2 methods.
(1) nmcli
(2) hostnamectl
NOTE: changing
hostname can also cause to change the configuration in several areas like
replacing the old hostname with new one in dns server or hosts file etc.
Types Of Hostnames
Linux system now has 3 types of hostnames configured:
(1) Static Hostname: Stored in /etc/hosts file or we can say the hostname set by kernel. Typically, service use this name as the hostname
(2) Pretty Hostname: A descriptive name or a user-defined hostname, such as proxy centre in data centre A.
(3) Transient Hostname: A fall-back value that is typically received from the network configuration or how the network views our system.
nmcli Utility
This utility is use to update the system hostname however other utilities might use a different parameter such as static or persistent.
STEP 1: Display current hostname
[root@oratest ~]# nmcli general hostname
oratest.localdomain
STEP 2: Set new
hostname
[root@oratest ~]# nmcli general
hostname oraview.in
NOTE:
oraview.in in above command is the new hostname
STEP 3: Network manager automatically restart the system-hostnamed to activate the new name. however, below manual action is required if we don’t want to restart the host.
[root@oratest ~]# systemctl restart network.service
STEP 4: Validate
hostname
[root@oratest ~]# hostname -f
oraview.in
[oracle@oraview.in db_1]$ ping -c 2 oraview.in
PING oraview.in (192.168.10.12) 56(84) bytes of data.
64 bytes from oraview.in (192.168.10.12): icmp_seq=1 ttl=64 time=0.206 ms
64 bytes from oraview.in (192.168.10.12): icmp_seq=2 ttl=64 time=0.039 ms
--- oraview.in ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1064ms
rtt min/avg/max/mdev = 0.039/0.122/0.206/0.084 ms
hostnamectl utility
Another available method to update the hostname is hostnamectl utility.
STEP 1: Display hostname
[root@oraview
~]# hostnamectl status --static
oraview.in
STEP 2: Change
hostname using hostnamectl utility
[root@oraview
~]# hostnamectl set-hostname oracleview.example.com
STEP 3: Restart network service
[root@oracleview
~]# systemctl restart network.service
NOTE: Active
shell users must relogin to take the effect.
STEP 4: Validate
new hostname
[root@oracleview
~]# hostname -f
oracleview.example.com
