[Dovecot] Dovecot 1.2/2.0 coexistence guide?

[Ron Leach]

Ralf Hildebrandt wrote:
> * Ron Leach <ronleach at tesco.net>:
>> Ralf Hildebrandt wrote:

>>> I'm switching back and forth between 1.2 and 2.0. No need to worry.
>>>
>> Ralf, on the same server machines - ie, switch off 1.2, start 2.0, or
>> on different servers, one running 1.2, another running 2.0?
> 
> Of course on the same machine.
>  

Fair enough.  I was thinking of using 2.0 as a 'new system' during a 
general migration to both:
(a) new server hardware, and
(b) updated OS - not wanting to upgrade the OS in-situ with critical 
applications running

>> And, in your case, where are the user maildirs?  On the same machines
>> as the servers?  Somewhere else?
> 
> In my case on the same machine, but since both 2.0 and 1.2 use the
> same setup, how does that matter?
> 

I wouldn't start to guess - I know relatively little.  But I was 
interested in your experience, and opinion; it's clear from many of 
your contributions that you're running some serious systems, and just 
thought to ask.

In essence, just trying to see if the co-existence principles, that 
the OP was thinking about, would help or hinder in the more general 
problems of migration of architecture, especially if the dovecot 
server were to be migrated elsewhere while leaving the maildirs 'where 
they were' and able to drop back to v1 in case of problems.

(Migration to different system arrangements is really a topic in 
itself, and I don't want to hijack this thread, just explaining what I 
was thinking around.)

Thanks for the reply, Ron