When doing quick maintenance tasks on a server, you can use the following approach to keep your site available:
- Failover the backnet IP address of the host to another host
- Use arping to tell the network that this IP was switched
- Remove the IP from the host that needs maintenance
In case you do not have a full high availability setup available, you can use ipswitch, a small tool I wrote to assist with this kind of simple failover tasks.
You can install it using
$ gem install ipswitch