I have a domain bothner.com with various subdomains all of which I've been hosting from my home server. I'd like to have the bothner.com hostname map to my existing home service, but serve web pages from dreamhost. Most of my web pages are in subdomains, so they can be easily directed to dreamhost, and I can use a redirect on my home server to map a relatively small number of web requests to dreamhost.
The problem is DNS: I can solve it using an external nameserver that resolves bothner.com to my home machine, and the various sub-domains to dreamhost. However, that doesn't seem like a stable situation, since the dreamhost IP address can (I gather) change with no notice. So it is better to use dreamhost's nameserver. But is that possible? I can certainly add a new A record for bothner.com that points to my home machine. However, that yields two A records for bothner.com, since dreamhost doesn't supress the automatically-generated one in this case, and I suspect that wouldn't be robust.
This isn't a feature I can't live without, since had planned on instead using a new subdomain for my home machine. However, that does mean I have to change a bunch of things, including generating a new certificate.