[imp] Server Farms..

[Michael Bellears]

We currently run one (very!) overburdened IMP server (Currently wearing
many hats - qmail/courier-imap/anti-virus/spamassassin/webmail on Debian
3) - So we have decided to migrate to a server farm.

We have been looking at the following Loadbalancers(If anyone has
personal experience with either, or other recommendations - I would be
grateful for any input):

ServerIron-XL -
http://www.foundrynet.com/products/webswitches/serveriron/
CoyotePoint - http://www.coyotepoint.com/equalizer.htm

I have a couple of questions regarding the "real" webservers setup:

1. We currently run MySQL for IMP prefs/vpopmail users/spamassassin
prefs etc - Is it advisable to have each "real" server run it's own
MySQL - And have each in a master/slave setup?

2. What is the recommended method to synch config files on all "real"
servers (Eg. Httpd.conf, horde/imp config files etc?) - Have only one
server that admins connect to for mods, then rsync any changes to the
other servers?

3. What about logfiles - We would have all users mail etc on an NFS
share - Can you do the same for logfiles?(Or do you get locking issues?)
- From a statistical aspect, it would be a pain to have to combine each
"real" servers logfiles, then run analysis. Also from a support
perspective - How are support personnel supposed to know which "real"
server a client would actually be connecting to in order to see if they
are entering a wrong username/pass etc?

4. This is OT, but I thought I would ask anyway - Once we have a "real"
server setup they way we want - What imaging software can be used (Quick
recovery in the event of server failure (Eg. If Total rebuild is
necessary), and also simple for addition of new "real" server)?. I would
love a utility that can create a bootable CD from our SOE, giving us the
ability to just place this CD into the new server, power up and in a
couple of minutes we have a fully functional server ready to be placed
into the server farm.

I have briefly looked at the following :

http://www.mondorescue.org/
http://www.systemimager.org/

Thanks in advance for any input.

Regards,
MB