i think i misunderstood what you were saying -- i was confused because i think you were talking about 2 different things.
let's take your comments one at a time.
Might I suggest a test then sometime so that people can verify they can access it before it is needed?
the backup forum is online, you can go now and verify that you can access it, and bookmark it; it's on a different server and so should be available even if main server crashes: http://forum.dcmembers.com/
Also, isn't there some way to put up a default message to tell people instead of the default 404 error message?
if you're point is that when the main donationcoder server crashes, couldn't we put up a link on the main donationcoder.com server to the backup forum that people could click. this will depend. if the entire server crashes, this isn't easily possible because of DNS/nameserver propagation delays, etc. If we can, we will. But if things go really wrong, it won't be something we have control over. that's why it's important for people to make note of the url now. Also pays to remember our irc chat channel (#donationcoder on efnet) which is an alternative place to go.