www prefix with subdomain

[penguen]

Hi i have a vps with fedora.I want to configure my subdomains as www.subdomain.domain.com how can i add www prefix for subdomains

[falko]

Do you run your own name servers, or does your registrar/someone else do it for you?

[penguen]

thanks for your reply i am not quite sure about that they told me i have full control over dns and i have a bind server so i thing yes i run my own dns server.But you can help me for both ways :)

[falko]

You can find out about the name servers for your domain by running
dig ns yourdomain.com