DirectAdmin Support said:
You could simply setup one account on each server as normal, then add 2 A records wherever your DNS server(s) is/are located, pointing the two duplicate records to each of the 2 accounts.
As has been discussed many times on the bind-users list, this does not give redundancy.
It gives you some load balancing, as the nameserver will give alternate A records each time it's called.
But it will continue to do that even if the server the A record is pointing to is down, with rather complex scripting (done outside of bind) to check the server every minute or so, and if it's down, then remove the A record from the zone file and reload the bind zones. (It also requires a quite short TTL, perhaps under five minutes.)
A much better way (that will give both some load balancing and redundancy) is this way:
1) two webservers hosting the account
2) Each server hosting not only the website but the DNS
3) Each webserver providing only A record for itself.
4) Registry (where the domain is registered) listing both nameservers
5) Again, very short TTL.
The way DNS works, is when someone tries to find the site, both nameservers will be returned, and queried.
The local user's computer will use the DNS record s/he gets back first, and will then point to the site in that A record.
If the server goes down, the DNS goes down with it, and only one DNS server will return a response, and it will return the A record it hosts.
There's a problem with this method as well; most browsers don't clear DNS until they're shut down, so if you're looking at the site and it goes down you'll have to restart your browser before you can see it again.
There are other ways that are more foolproof, but they require rather complex and expensive solutions.
For example, this is precisely what Microsoft's Active Directory does; it separates servers from their DNS records. Of course if the Active Directory server goes down, you're still dead in the water
.
Jeff