Re: Mail clustering

[Michael Loftis <mloftis@modwest.com>]

--On March 20, 2007 4:37:25 PM +0100 Cherubini Enrico <kevin@bestkevin.com> 
wrote:

> Ciao,
>  Tue, Mar 20, 2007 at 04:27:36PM +0100, Marek Podmaka wrote:
>
> thanks for your reply.
>
> > First you should identify what is your bottleneck. Is it postfix? I
>
> the bottleneck is the hardware, a dual xeon 3.20GHz with 2GB of ram, that,
> is pretty high on load in the antivir/antispam server (of course).

I'd ascertain what kind of load.  If it's I/O, NFS will likely make it 
worse since NFS increases latency to disk by huge amounts.  Also I've had 
some serious issues with the 2.6 NFS server and have stayed on 2.4 for our 
NFS server because of this.

A machine that size should be able to handle a LOT of scanning.  2Gb of ram 
though is really anemic for high mail volumes with AV/AS.  I'd suggest 4Gb 
or 8Gb.  Run vmstat and watch it, see if you're swapping, see how much 
cache you're using.

> > RBLs). IMAP/POP3 can use some disk + CPU for sorting emails. But
> > usually the bottleneck is antivirus/antispam. So until you get disk
> > bottleneck I think one server for smtp + pop3/imap is enough and you
> > can use many servers for antivir/antispam. Which solution do you use?
> > Does it permit to define alternative hosts for antivir/antispam?
>
> as for the a/a server, we use postfix+various dnsbl+amavis+clamav (postfix
> patched for quota support), while the "standard" server is the same
> without dnsbl and all antivirus things.
>
> My idea is to use two servers, ie for the a/a, with round robin, to be
> able to balance the load because I'm sure that in a few months even a more
> powerful server reache the limit, without changing anything else in
> customers configurations, dns zones, and so on.
>
> --
>
> Bye Enrico
>
> Elefante: un topolino progettato secondo le indicazioni del governo.
> 		-- Robert Heinlein



--
Michael Loftis
Modwest Operations Manager
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