Building a fail-over server

I'm looking to set up a fail-over server at a second location for our main DirectAdmin server. Our colo provider has already told us that they can easily reassign our server IP to our second server once the primary fails, but I'm wondering if anyone here has experience with this kind of thing, and how best to go about it?
We're currently running FC2 on the primary server. Would we need to somehow use a different filesystem for this stuff?

I don't actually need to have the entire system fail-over. It's fine with me if the second box only provides HTTP, MySQL, and accepts mail (which it will route to the primary once it's back up). Of course, having complete redundancy would be even niftier, but I'm guessing we'd have to reinstall the entire server for something like that, right?

I am looking to do the same thing, any help or experience would be greatly appreciated!

Tell us how you'd handle the routing of the mail to the second server, since you want both servers on the same IP#?

It gets a bit more complex since DA can only install one license per IP#.

Yes, you'd probably need two complete servers, running DA and all the other software, to do what you want.

Plus some level of complexity to do the routing, swap IP#s, etc.

And you'd have to shut down one of the servers, or convert it to another IP#, long enough to install DA on the second server at the same IP#.

Which would put you in violation of the DA license.

So you'd probably be better off with another IP# or set of IP#s, a fallback mechanism to change DNS (this can be quite easy), a very short TTL for DNS, etc.

And you'd still have a few single points of failure. And some people who will not be able to connect because their local systems, their ISPs, or their routers, just won't give up the old IP#s easily.

This is asking a lot, and there are some very good reasons why redundant hosting usually costs significantly more than twice non-redundant hosting.

Jeff

I misread, I would definately have two IPS, two seperat boxes, basically just want to have httpd and mysql running and catch the mail, so if the primary box shuts down it will get the mail once its back online from the secondary server, even if the second server was 12 hrs behind on updating, meaning have it update every 12 hrs the httpd. Maybe this will help understand better what I would like to do.

Well, at least now it's possible. Do you intend to own two DA licenses? If so, then at least you won't have to build a complete httpd environment from scratch.

But you will have to have duplicate httpd and exim environments, including all users, etc.

What specific questions do you want to ask?

Jeff