Step 1: Login to your VPS
Locate the IP address of your Vultr VPS and login as the root user.
ssh root@server
Step 2: Use the hostname utility
Change your hostname to a different name of your choosing. For example:
hostname server01
Step 3: Edit /etc/hosts
Open the /etc/hosts file with your favorite text editor. For example:
nano /etc/hosts
Change the first line and replace your old hostname with the new one. Save the file and exit the editor.
Step 4: Edit /etc/sysconfig/network
This file also contains your hostname. Open the /etc/sysconfig/network file with your favorite text editor.
Change HOSTNAME=vultr to your desired hostname. For example: HOSTNAME=server01.
Step 5: Check your hostname
Run the following command to check your new hostname:
hostname
The new hostname will be displayed in your ssh terminal.
Step 6: (Optional) Change reverse DNS
Visit https://my.vultr.com/, then navigate to your VPS. Click on the IPv4 tab. You will see an "Update" button in the "Reverse DNS" column. Click this button to update the reverse DNS address. By default it will read:
x.x.x.x.vultr.com
It is common to replace x.x.x.x.vultr.com with the DNS name of your server, which may be related to its hostname.