How to configure subdomains on a VPS server?

The process for configuring a subdomain on a VPS server can vary greatly depending on the type of server and control panel you are using. However, a general guide for Linux server using Apache (most common scenario) is as follows:

Here is a simplified step-by-step guide on how to do this:

1. Login to your VPS via SSH.

1. Navigate to Apache directory (like `/etc/apache2/sites-available/` by using the `cd` command).

1. Create a new configuration file for your subdomain by typing `sudo nano example_subdomain.conf` where “example\_subdomain” is the name of your subdomain.

1. Enter the following basic subdomain configuration, replacing “subdomain”, “domain_name”, and “directory_path” with your details:

```
ServerAdmin webmaster@localhost ServerName subdomain.domain_name.com DocumentRoot /var/www/html/directory_path ErrorLog ${APACHE_LOG_DIR}/error.log CustomLog ${APACHE_LOG_DIR}/access.log combined

```

1. Save and close the file by pressing Ctrl + O, then enter, and finally Ctrl + X.

1. Enable your new virtual host with the command `sudo a2ensite example_subdomain.conf`.

1. Restart your Apache2 server to make these changes take effect by typing `sudo service apache2 restart`.

Remember, this only works if your DNS provider is pointing to your VPS IP. If not, you need to create an A record that points your `subdomain.domain_name.com` to your VPS IP address.

Also, this setup may be different if you’re using different software or a managed control panel like cPanel or Plesk. In those cases, subdomains are usually set up within the control panel’s interface. Please refer to the documentation of your specific control panel.