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Re: Sugesstions building a rather big mail system.

Am Die, 2003-10-07 um 22.07 schrieb Alex Borges:

> For example, we will use two Dual-P4Xeon 2Gb for the IMAP/POP, same for
> the SMTP (same kind of server, but another two servers).

Depending on what you want to do on the SMTP server (i.e. spamassassin,
scanning for viruses, filter, auto-reply, ... ) you may need more boxes
to handle the load.

> Then, the apache (which i am most afraid about) are the ones that spell
> trouble BIGTIME. This is because php/sm will prove to be the most
> resource intensive application in the farm (SMTP is simple, IMAP is
> simple). So we give it three of the same boxen and its own dual pair of
> LVS.

I think the second pair of LVS balancers is overkill. Balancing (even in
NAT mode) needs hardly any resources. Use Gbit interfaces if you think
you'll get more the 100 Mbit Network I/O...

> THen, the backend, this will be two failover enabled boxes with postgres
> and openldap. They will be quad xeon 6GB ram. 

Isn't a QUAD Xeon just plain overkill?
I haven't tested a setup with OpenLDAP, but a Postfix/Courier/MySQL
setup will generate "simple" queries wich any decent server should
handle without any problem even at a rate of some thousand per second.

> All of that, goes to the SAN. The local storage in each server should
> respond mostly to services cache necesities (a php cache for the apaches
> perhaps).

Think about splitting up the storage into multiple devices. 120k user
will generate a lot of I/O on the disks - you'll need a REALLY fast
disk-array for that (not bulk transfer but I/O per second).

best regards,
Markus Oswald <moswald@iirc.at>  \ Unix and Network Administration
Graz, AUSTRIA                     \ High Availability / Cluster
Mobile: +43 676 6485415            \ System Consulting
Fax:    +43 316 428896              \ Web Development

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