Simon Josefsson wrote:
>
> It is cheaper to buy another PC than to buy another CPU and add the
> CPU to your existing PC, so I would like to have two Cyrus IMAPD
> servers that mirror each other. Is this possible? Is the "Cyrus
> murder" related to this? From what I remember, it was only a
> front-end to multiple but separate servers, but I didn't really
> install and use it so I may be wrong.
>
> It is also better from a fail-over point of view, I want my mail
> server completely mirrored in two different physical locations. Right
> now, if my IMAP server crashes, I lose. Receiving mail is not a
> problem, sendmail queues them up fine and I can have backup-MX's, but
> I can't read my mail until the server is up.
>
> I'm thinking about a daemon that synchronizes the /var/spool/imap
> directory tree between machines, either with cooperation with Cyrus
> IMAPD or not. You probably don't need to hook into Cyrus IMAPD, but
> perhaps the performance can be increased if you do. It feels like a
> weekend hack, which is about the amount of time I have for it. :-)
Well, you'd also have to sync /var/imap so you'd keep the mailbox db,
seen state, subscriptions and quotas in sync. You'd probably have to
quiesce Cyrus so that no mail gets delivered, read, moved, etc.
You could use rsync to do the replication or I believe that there are
some network RAID1 solutions out there.
If I was going to do this myself, I'd get myself a dual ported FC RAID5
box, and setup a SAN with my 2 servers both talking the RAID5. You'd
need some SAN software to share the filesystem. Something like SGI's
CXFS *should* work nicely.
Ken
--
Kenneth Murchison Oceana Matrix Ltd.
Software Engineer 21 Princeton Place
716-662-8973 x26 Orchard Park, NY 14127
--PGP Public Key-- http://www.oceana.com/~ken/ksm.pgp
