Renaud Allard wrote:
> Hello Nigel,
>
> On Mon, 27 Apr 2009 15:32:49 +0100 Nigel Metheringham
> <nigel.metheringham@???> wrote
>
>
>> I'd appreciate a few pointers towards mechanisms/packages/ideas for
>> doing this to ensure I don't miss any possibilities.
>>
>> We have a requirement for a mail server (SMTP receive, POP collection,
>> IMAP not currently required) with a presence in 2 data centres, and
>> able to maintain operation if either data centre or the link between
>> them is unavailable. The ability to reconnect disjointed data centres
>> without data loss (we could tolerate some resurrection of deleted
>> messages) would be needed. There would be a huge number of
>> mailboxes, but low activity on each mailbox - aggregate activity is
>> not that high.
>>
>> Any ideas or suggestions?
>>
>>
>
> I used to have this kind of system working using unison
> (http://www.cis.upenn.edu/~bcpierce/unison/) for the two way replication.
> Assuming the messages don't change once they are written to disk, you can
> configure unison with a good performance. I would suggest you to take the latest
> development version of unison as it has some improvements on how conflicts can
> be solved if they occur.
> You will of course need to use a Maildir storage for this to work.
>
>
>
That unison looks interesting. I'm just wondering - is it better than
just running rsync if you just want to get a backup of maildir
directories every hour or so?
