On Wed, Mar 14, 2012 at 10:49 AM, Miles Fidelman
> Hi Folks,
> I'm currently running a pretty basic high-availability configuration for our
> mail server (postfix) - it simply runs in a Xen virtual machine, with
> mirrored disks across two machines (DRBD), and failover of the VM if
> something goes wrong (pacemaker).
> I'm thinking about migrating the failover host to a 2nd datacenter - which
> makes disk mirroring and VM migration a bit trickier, and I really don't
> like how brittle all that infrastructure is, so I'm starting to think about
> application layer redundancy - two mailservers, at remote locations,
> multiple DNS records, and doing something to replicate ques, configurations,
> and local delivery. The goal is the same: keep processing mail if a
> machine goes down, and don't lose any data to machine or disk crashes.
> Which leads to a question: Are any of you running such a configuration? If
> so, can you describe what you're doing? And.. are there any good
Well, first question here: how much traffic are you going to handle?
And now, my experience (please, postfix-list purists, stop reading
now, this is more related to DRBD than it is to postfix):
I have a HA cluster with two nodes on two locations, on softlayer, due
that softlayer provides unlimited inter-server connectivity (please,
if someone knows another hosting company that does this -unlimited
communication between servers in different DCs-, let me know:
softlayer is quite expensive), I'm just using the private network
(that use to run at 200~500Mbps) to replicate the DRBD volume. I had
several issues, but I suggest you try, and then post on the
corresponding lists (DRBD, pacemaker, corosync, heartbeat, ....). I
have VM-level failover here, but it is pretty much the same to setup
About multiple DNS records, etc... I just used low TTL DNS, and a
dynamic DNS setup, so that the VM updates the DNS record on failover.
On a side note: I personally believe that service-level HA
configuration is better than VM-level.
> references, presentations, etc. that anybody knows about re. building
> high-availability, scalable, distributed mail processing infrastructure?
You can use postfix's mail routing capabilities to have distributed
mail processing, ie: have some users on one server, and others at the
other server... it is neat.