--On 9 November 2007 12:50:43 +0100 Adrian Chapela
<achapela.rexistros@???> wrote:
>
> You also can use DRBD and heartbeat to achive high availability with two
> servers. You can replicate mailbox and spool with DRBD and with
> heartbeat you can use only one IP for two servers and you only have a
> active server. This is a good solution for your local mail clients.
>
> Best regards.
Provision of IP failover is highly dependent on the platform that you're
using. It's not required for MX availability, because remote servers will
try all your advertised servers. It is required for MSA availability,
because MUAs will not.
We use MacOSX servers. OSX has a reasonably easy to configure IP failover
mechanism, as long as you only have two servers. When we went beyond two
servers, we deployed spread and wackamole which make failover
configurations for any number of servers trivial. For example, we have 12
imap server IP addresses, to ensure good load balancing with either 4, 3 or
2 available hosts. Wackamole simply needs to know what the addresses are,
and endeavours to share them out equally among available servers.
<
http://www.spread.org/>
<
http://www.backhand.org/wackamole/>
--
Ian Eiloart
IT Services, University of Sussex
x3148
