[Dovecot] DSYNC needs a lot more documentation

[Marc Perkel]

On 8/21/2010 9:16 AM, Timo Sirainen wrote:
> On 21.8.2010, at 16.24, Marc Perkel wrote:
>
>> Started looking into the dsync utility and the doc are seriously incomplete. I can of course scour the internet looking for the missing information but that doesn't fix the problem with the docs. I might try to rewrite the docs myself once I figure it out.
> Or you could mention some of the things you think are incomplete.
>
>

Ok - when I type dsync at the command line it says:

usage: dsync [-C <alt char>] [-m <mailbox>] [-u <user>] [-frRv]
   mirror <local mail_location> | [<user>@]<host> | <remote dsync command>

However the man page mentions nothing about any remote commands. There 
is a reference to ssh in one example but there isn't any kind of 
overview as to how this all ties in. Does dsync pick up information from 
dovecot.conf or dovecot to know where the email is an what format it is 
in? Does dovecot need to be running on both ends? Does this run 
continuously once you start it or does it need to be run once a minute? 
The information in the man page isn't complete enough for me to even 
figure out what to ask.

When you write software you never have to learn it so you don't have the 
perspective of someone who never heard of it before and wondering "what 
is this?" I can probable figure it out if I read enough of the message 
from the dovecot lists but the docs should be complete enough so I don't 
have to do that unless I'm doing something very weird.

So - ServerA is running dovecot. On ServerB I want to have a live copy 
so that if the drives on ServerA die I can recover on ServerB? Does it 
do that?

I want to run dovecot on two servers so that if either server fails the 
other seamlessly takes over and when the other comes back up they resync 
as if nothing had happened. Is that possible? If so - how?

If it just does backups, how is it different than rsync?

Anyhow - just letting you know from the perspective of someone who knows 
nothing and exploring it for the first time. I wanted to say this before 
I learned anything more about it.