How to choose mail server hardware
 

Hi all,

I need to configure a mail server. But i am not sure how to choose
hardware for this server. Here is the list of software and services
I plan to install:

Qmail
Vpopmail (With MySQL support)
Webmail (Squirrelmail)
Qmailadmin
Vqadmin
Clamav + Qmailscanner
Spamassasin

Apache 1.3
MySQL 4
Bind 9

This server will be a mail server for a hosting company.
It will be used to host over 300 domains.
Web server will be used only for webmail, qmailadmin and vqadmin.
There wont be any zone definitions
for DNS server. And also MySQL will be used only for vpopmail (virtual domains)

So what kind of hardware do i need? What could be the parameters for configuring
this server. Since i have limited budget, i want to use resources effectivelly.
I will really appreciate if someone shares his/her experience or if someone
advise me.

Thank you.

-ozgun.

The only real overhead you may run into on the mail server part of the equation is the qmailscanner (perl) scripts + SpamAssassin/ClamAV. Mail doesn't usually require a lot of horsepower, but lots of processing of it can start to give you grief, usually during a nasty email virus outbreak.

The next thing to look at is the Apache+Squirrelmail+MySQL. The MySQL load on this should be relatively light as it's only used for authentication. Squirrelmail (php) on Apache seems to be a decent performer and you may want to look at some simple compression as well.

I'm guessing that you're looking for rackspace and are probably paying by the unit, so a 1U server would be the most economical. I'd look for something tha can hold at least 3 drives, 4 is better. You'll want to span the most active filesystems on different drives to reduce bottlenecks. Some of the most active directories will be:

Mail - (something like /home/vpopmail)
qmailscanner (working, temporary and quarrantine directories)
Temporary directories for Squirrelmail session cache data
Apache and php logs

Of course this doesn't really leave any room for any kind of RAID configuration, so you should proably lean towards the best drives you can afford (SCSI or at least high-end serial ATA) and have some kind of plan in place for disaster recovery. Redundant power supplies should also be a requirement - you don't want 300 cusomters banging on your pager when something goes horribly wrong :)

Hi mcleodnine,

Thank you very much for your reply, and I'm sorry that i couldn't reply quickly.
You really mentioned about most important isssues.

As you ques I think a 1U or 2U rack server would be a good solution. But i think i have to make a decision between security and performance, so i havent decided how to use disks. On one hand, raid seems ok for security but on the other hand, in order to increase performance, using these disks for vpopmail directory and qmail-scanner log and temp files seems ok too.

I tkink another important issue is the memory. I know that qmailscanner, clamav and spamassasin consumes lots of memory. And I can't be sure if 1 GB memory will
be enough. Any ideas?

And lastly, do you have any suggestions about CPU, for example one 2.4 or 2.8 GHz Xeon could be enough? Or do i have to use 2 CPUs?

Thank you very much again for your suggestion.

-ozgun.