[wplug] Mailman and Postfix

[Jonathan S. Billings]

Hi,

I'm going to give a birds-eye-view of what I'd do.  I used to manage
the mail @cs.cmu.edu, so I've done a bit of moving mail services from
one set of hosts to another (although mostly from MMDF to sendmail).

On Wed, Jan 23, 2008 at 11:18:05PM -0500, Michael Semcheski wrote:
> Questions include (but certainly are not limited to):
> How do we move the mailing lists and archives off of penguin.wplug.org
> to linode.wplug.org?

First, install postfix and Mailman on linode.  I suggest copying over
everything in /var/mailman from penguin to linode.  This will get the
archives and list configurations in place.  Hopefully, the version of
mailman on linode will just accept the configuration from penguin,
otherwise you're probably going to have to copy over configurations
bit-by-bit. 

You'll need to port over the postfix configuation too, but I'm a
sendmail guy, I can't help there.  I see that penguin is running
sendmail, so you'll need to actually find someone who knows what
they're doing to generate the correct postfix configuration.

I suggest that you set up postfix and mailman to be as
linode.wplug.org for testing purposes, and you send some mail to one
of the mailing lists (wplug-internet, for example) and see how well it
works.  It'll probably take a bit of time as you get familiar with
running a mail server.  Don't move the DNS records until you're sure
it's working.  Once you're sure, then you can shut down postfix and
mailman and change the configs so they think they are wplug.org.

> When do we change the DNS records and how do we coordinate that with
> moving the lists?

I see you don't have an MX record for wplug.org.  I suggest creating
one NOW, referring to penguin.wplug.org and with a low TTL, like 5
minutes, so you can switch it over quickly when you do want to make
the move.  That way, when you want to move the lists over to linode,
it's as simple as updating the MX record with the new A record.

Keep in mind, once you move the MX record for wplug.org, ALL mail
going to wplug.org will start arriving at linode, not just list
traffic. 

> How do we make sure we get everything moved over?

Fortunately, if you set up the MX record right, it'll be trivial to
switch back to penguin if something goes wrong.  I suggest that when
you want to make the move, do it when you have several days ahead when
you can be ready to fix problems.  

I suggest announcing the switchover to the list, shut down mailman and
sendmail on penguin, update the DNS records and watch for incoming
connections on linode, and debug any problems you encounter.  Send out
a new message to the list saying the transfer is complete. 

-- 
Jonathan Billings <wbanguna at gmail.com>