VPS backup server, is it possible?

I have a dedicated server and I want to buy a VPS for backup purposes.
Not for copying backup files, my idea is to have a site replicated in two servers (in the dedicated server and in the vps).

So I want to setup my domain with alternative nameservers that will be located at the VPS.

So my domain will look like this:

www.domain.com
ns1.domain.com
ns2.domain.com
ns1.vpsname.com
ns2.vpsname.com

In case of failure the DNS will start to resolve the alternative ones isnt it? ns1.vpsname.com and ns2.vpsname.com, showing the website online and email accounts keep working.

So when the main DNS is up again, when you request the site it will see that the main DNS are up and will show the site that is stored at the dedicated server.

Am I wrong or is ok?

For the other side, is there a way to restore a backup in the VPS, but only restore the email accounts and domain without data? Cause cpanel when you restore an account it deflates the homedir with all the content and I want to do is to restore domain (without the info at public_html) and the mail accounts.
I think cpanel didnt implemented this yet, but It would be nice to have it as a feature.

Thanks!

 

But in the way I want to do is possible, note that the dedicated server is in one datacenter (Atlanta) and the vps is in other datacenter (Texas).

Is to avoid more like network problems, hang ups and all that stuff. And at least have the accounts replicated in other server with mail working. Is better than having 100% of the service down :D

 

Other doubt I have. My main domain and their respective NS names are at godaddy.

www.domain.com
ns1.domain.com -> points to a main server ip
ns2.domain.com -> points to a main server ip


I dont want to register other domain, cause I would like to use the same domain for the records, cause I dont want to have a mess of servers all with different ns.

My intention is to have other two ns at godaddy:

ns3.domain.com -> pointing to a backup server ip
ns4.domain.com -> pointing to a backup server ip

The question is, the backup needs to have the main domain created in the system?

The situation is the following, a site has the four ns records loaded.
So if main site is down, the ns1 and ns2 will be down too including the domain of the ns.

The backup server will respond anyways although the main domain is down?
Other thing which hostname should I use for the backup server?
Main server hostname is server.domain.com I would like that backup hostname be backup.domain.com

Do I need to create a godaddy ns record with the "server" name?

Sorry for the questions cause I never did this before.

Thanks