Redirect to offsite server during downtime

[ephigenie]

ok - in this kind of setup is pretty simple ...
just create a hot-standby clone with drbd + Heartbeat and you're done.

and if there's more then one server (whose dns is to change) it gets pretty ugly without a multi-server-panel right now.

And then if you actually get to reroute your traffic into another facility for sure you're kind enough to tell your firewall to forward every packet for a server with unexpected downtime onto a highspeed single-threaded nginx/lighttpd/ tux machine with a static "out of order" page or similar (apache2.2/event_mpm with mod_mem_cache may apply as well)

That way - you don't have the hazzle of possible dns inconsistencies and : when you're first facility is up again your preferred route is up again and upstream routers will prefer that route - so your online again without throwing a bomb at your firewall again