Could anyone point me in the right direction on this concept?

I would like to have two linodes that serve the same purpose of hosting web and email. The goal would be if one failed the other would pick up the slack Can this be done with DNS? Just simple vhosting and email filtering/storage would be perfect.

I'm experienced with linux - so any solution I would entertain.

Thank you

For the email server it should just be a question of putting the second server in the DNS as an alternative MX record.

For web / imap / etc, I can see three ways you could do it:
- Make your TTL very short, and manually change the DNS when one server goes down. Not great because when the server goes down you might be asleep :-)

- Put both servers in the DNS (like google.com has 3 entries), and they would be used on a round-robin basis. I think modern browsers will try the second server in the list if the first one doesn't respond. This is 'poor mans load balancing / redundancy', and actually works quite well. Disadvantage is the users have to wait for the first server to timeout before they get to try the second, and some apps may not automatically fail over.

- The really cool way: IP address takeover. http://www.onlamp.com/pub/a/onlamp/2003/04/03/linuxhacks.html
This is what we do at work, using a commercial product, the Zeus ZXTM. Really you want both machines on the same network, with two separate connections between them.

I would probably try the round-robin DNS first, as IP address takeover with Linodes might be quite challenging.

Let us know what you end up with.

I think the round-robin dns trick will work. I suppose for email I could set different preference level on the email and essentially it will look to the second server. The only thing I feel I'd be missing is that ability to train a spam-assassin filtering server.

I suppose I could just put up a good server here to do spam filtering... :/