>>> Very. We have a single Linux box facing the Internet which >>> runs everything through postfix, amavisd, and clamav to weed out >>> the phishing and worms that attack the Microsoft virus, Windows, >>> then hands off messages that pass to the internal cluster using >>> round-robin DNS as the poor-mans load balancer. This box runs >>> with a load average less than 1.00 most of the time, rejects >>> close to 2 million messages a day on IP related tests, passing >>> about a half-million through to the internal servers which do the >>> spamassassin checking and delivery to the user's mail stores. >>> >> What processing and i/o power do you have on that box and how much RAM? >> For the front end boxes, I had about 20-30 dual PIII 800Mhz boxes with >> two SCSI disks and 1GB worth of RAM. They reject close to 180 million >> messages based on access and ip rules, header and body checks (so >> nothing cpu heavy) and they pass on about 3 million for routing or >> further processing. > > The border MX machine is running a Intel(R) Pentium(R) 4 CPU 3.20GHz, seen > as two processors in /proc/cpuinfo with 6389.76 bogomips. It has 2GB RAM, > and currently has a load average of 0.24 reported by top. I guess that is plenty for one third the volume of rejects one of those dual PIII boxes handled...but then your box handles five times as many deliveries and therefore scans... > > The hard drive is a 40GB WDC WD400JD-19LS SATA which isn't anything special > by any means. It's running SLES9, installed in February 2006. Uptime is > only 356 days as it had to be rebooted to move things around in the rack. You make sure emails never queue eh? > > The machines handling mail deliver in the cluster vary. The first one I > checked has an Intel(R) Celeron(R) CPU 2.66GHz with 1GB of RAM. These too > have pretty vanilla SATA drives. > > The main server with the home directories has an Intel(R) Pentium(R) 4 CPU > 3.00GHz with no SMP, 2GB RAM, and several SATA drives. > > The border MX isn't beginning to breath hard handling the IP access rules, > postfix, amavisd, and clamav. We have seen very even distribution amongst > the delivery machines in the cluster using nothing more for load balancing > than dnscache from djbdns for a single hostname on the private internal > 10/100 LAN. Heh, I cannot imagine any other software for dns caching. > > The attached image shows the size of the mail queues on each of the 4 > machines every fifteen minutes since midnight yesterday. This peaks > shortly after midnight when daily security scans and other maintenance jobs > are running. > > The load averages on these cluster machines rarely gets over 1.00. > The only times I had high load averages was when sendmail was in and when we are under bounce floods/ddos. I guess this is the cheapest and most efficient way to do email.