Date: Wed, 16 Sep 2009 14:49:28 +0100 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: Steve Bertrand <steve@ibctech.ca> Cc: "questions@freebsd.org" <questions@freebsd.org> Subject: Re: New mail server setup Message-ID: <4AB0ECE8.2080905@infracaninophile.co.uk> In-Reply-To: <4AB0E97B.4060606@ibctech.ca> References: <4AB0584D.3050206@eagle.ca> <4AB0844B.5080804@infracaninophile.co.uk> <4AB0E97B.4060606@ibctech.ca>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--------------enigD2C71DFF635354C4A7387636
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Steve Bertrand wrote:
> What I don't have, and have always wondered about, is live redundancy
> for the IMAP/POP services.
>=20
> I know that this would be a challenge to some degree considering the
> high volume of data changes.
>=20
> Perhaps a carp(4) setup between a couple of MDA's, where when the
> primary is up, a constant rsync pushes the data to the backup. Or
> perhaps a combination of rsync for manual changes, and a method to have=
> the primary write the emails to a local disk, and a network disk
> simultaneously?
>=20
> If anyone has a setup that has redundancy for their IMAP/POP services,
> and a method to keep the changing data relatively up-to-date, I'd love
> to hear about it.
Now, that is a different kettle of fish. This is a job for cyrus imap.
I suggest googling for 'cyrus murder' -- this is almost, but not quite,
a fully resilient mail store / IMAP system. Your mail store is divided
into frontend IMAP protocol servers which handle user auth etc. and back-=
end
mail stores. The protocol layer servers are fully resilient and you can
fail over a user session at will, but the mailstores don't quite get ther=
e:
mail is replicated across different stores, but actions modifying the mai=
l
store are not transactional across all the mail stores. Or in other words=
,
you can lose a small amount of data if one of the mail stores goes bang a=
t
precisely the wrong moment. Even so, it will do better at keeping multip=
le
copies of a mailstore in synch than any locally scripted rsync setup.
Cheers,
Matthew
--=20
Dr Matthew J Seaman MA, D.Phil. Flat 3
7 Priory Courtyard
PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate
Kent, CT11 9PW, UK
--------------enigD2C71DFF635354C4A7387636
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.13 (FreeBSD)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iEYEARECAAYFAkqw7O4ACgkQ3jDkPpsZ+Vaq3QCeO7tofnQr5/B/zqMndEG7VUaT
t74An1oHMysFJioBQJP9BqIAIYQCUloT
=sxed
-----END PGP SIGNATURE-----
--------------enigD2C71DFF635354C4A7387636--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4AB0ECE8.2080905>