On Oct 23, 2004, at 4:50 AM, Ean Kingston wrote:
> On October 22, 2004 01:10 pm, Ralf Hildebrandt wrote:
>> * Faustino Benitez <tinuscubensis@...>:
>>> Hi there,
>>> I've been setting up a Courier-imap with postfix and everything is
>>> working pretty well. I want now to keep a real-time synchonization
>>> between to machine in order to have a backup system ready to run.
>>> Any suggestion on how to do a synchronization between two MailDir
>>> filesystem, in real-time?
>> I'd run rsync very often
> I would connect both machines to a common SCSI disk sub-system and
> configure a
> RAID-1 (mirrored) pair (or more) of disks for the Maildirs. Then have
> to run on the 2nd system to take over controll of the disks if the
> system goes down.
This really is the best solution, and is the most accepted way to solve
this problem in the industry.
I've used the heartbeat system before to do the failover part:
I recommend you use that to do the actual failover as its more robust
than writing your own scripts (though, its not that hard, to be
Also, thinking about it, you could look at some kind of Cluster
Filesystem, like OpenGFS, which would theoretically allow both nodes to
have the same filesystem mounted at the same time, with locking and
cache coherency problems solved. Cool, huh. I've never seen it work
(because I've never tried it) so I'd love it if someone could verify it
(Out of the scope of this list, though)