Have an virtual private server working as a webserver?

then you have Apache (httpd) probably.

After VPS is moved to another dedicated server, HTTPd service might not start complaining:

Code:
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using * for ServerName
This means one need to open /etc/hosts (vi /etc/hosts) and find an line starting with VPS IP.

This IP must be your new VPS IP and after space enter fully qualiffied hostname (it means phrasse with two dots) like: host.mydomain.tld
Such FQDN hostname dont need to exist at all but Apache just want it.

Example /etc/hosts after fix:
Code:
127.0.0.1 localhost.localdomain localhost localhost4.localdomain4 localhost4 autoreply.sub.domain.tld test sub.domain.tld
# Auto-generated hostname. Please do not remove this comment.
mynewiphere host.mydomain.com
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
then i set my linux server hostname to same fqdn by command:
hostname host.mydomain.com

Next thing is to start Apache (HTTPd):
service httpd start
or
/etc/init.d/httpd start

If you moved server to antoher IP, and you host some domains on server, then you need to:
1. login your web control panel (Webmin,Kloxo,zpanel,cpanel..) and find DNS section. There edit your domains to have new IP. Maybe try to restart named/bind service if necessary (service named restart)
2. login your domain registar control panel and change your nameservers IPs so it points to your new server IP.
Now domain point to your server IP and your server accepts the connections and serve the website from hdd