looking for Cyrus mail format documentation

[Phil Howard]

On Tue, Feb 04, 2003 at 10:19:27AM +0000, Mike Brodbelt wrote:

| Rob Siemborski wrote:
| > On Sat, 1 Feb 2003, Phil Howard wrote:
| >>| Doing replicated IMAP stores (espeically geographicly distanct ones) is
| >>| not an easy problem.
| >>
| >>It's easy if every message is a separate file.
| > 
| > This is not true.  It has nothing to do with the implementation of the
| > mailstore.
| 
| I've never actually had the need to try this, so caveat emptor, but I've
| heard of people having some success replicating Cyrus mailstores with
| drbd - http://www.complang.tuwien.ac.at/reisner/drbd/.
| 
| There are limitations to this approach which may make it non-viable for
| you - your machines would need to be Linux hosts, and you'd need a
| dedicated network link, but it's the most promising approach I've seen
| to "simple" mailstore replication between two machines so far.

I wonder how well that method of replication works when both nodes
cannot reach each other, and both are doing updates.  And I wonder
just how much bandwidth it uses.  Suppose one node is connected over
a 28.8k analog modem connection because for the rate of SMTP flow
in and out, it's enough.  Now adding replication delta, will it be
any more than what is locally added to the mailstore?  I would think
the block layer replication would blindly replicate every block on
the device that gets changed, rather than a small piece of metadata
that would only need to be sent if the replicator understands the
meaning of the change.

-- 
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| Phil Howard - KA9WGN |   Dallas   | http://linuxhomepage.com/ |
| phil-nospam at ipal.net | Texas, USA | http://ka9wgn.ham.org/    |
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