fault tolerant web servers on freebsd

[Maciej Jan Broniarz]

W dniu 10-04-05 22:43, jfarmer at goldsword.com pisze:
> Quoting Maciej Jan Broniarz <gausus at gausus.net>:
>> W dniu 10-04-05 22:08, Tonix (Antonio Nati) pisze:
>>> Maciej Jan Broniarz ha scritto:
>>>> W dniu 10-04-05 17:45, Mike Jakubik pisze:
>>>
>
> So first you have to define your workload, then define what errors you
> must avoid or allow, and then define how to deal with failures, errors,
> etc.
> Then you can start talking about High Availability vs. level of Fault
> tolerance, vs. ....

Let's say i need to run a few php/sql based web sites and I would like 
to maintain uptime of about 99,99% per month. No matter how good the 
hardware - it will always fail at some time. My goal is to build a 
system, that can maintain that uptime.

 From what You say I need some level of HA system, to maintain the 
required uptime.

So, as I've said earlier (correct me, if I'm wrong) - the setup could 
look something like that:

- 2 web servers with carp
- 2 storage servers with on-line sync mechanism running
- 2 mysql servers with on-line database replication

(i'm skiping power and network issues at the moment).

Few people have told me about a setup with linux, drbd and heartbeat 
which offers them some level of HA. Has anyone tried anything similar on 
FreeBSD?

mjb