[Dovecot] Dovecot 1.2/2.0 coexistence guide?

[Tom Talpey]

On 12/5/2010 2:25 PM, Timo Sirainen wrote:
> On 5.12.2010, at 16.40, Tom Talpey wrote:
>
>> I am running Dovecot 1.2.16 and considering moving up to 2.0.8.
>> I have found<http://wiki2.dovecot.org/Upgrading/2.0>  but there's
>> not a lot about deploying a 2.0 server alongside an existing 1.2.
>> Any hints on a seamless approach to this, especially one that might
>> allow me to upgrade individual users in place, without moving their
>> maildirs into a new tree and still avoid issues with 1.2/2.0 sharing
>> access?
>
>
> Added to wiki: Once running v2.0, it's safe to downgrade to v1.2.5 or newer. Older versions don't understand some of the changes to index files and will log errors.
>
> It's also safe to run v1.2 and v2.0 in parallel, even accessing the same index files.
>

Thanks. I was hoping to find an easy way to do the latter (run both
versions in parallel on the same server), since I want to migrate users
individually. It would be important to use the same locking settings
right?

It turns out to be rather a challenge to build dovecot 2.0 using
independent paths from 1.2, so they can be installed and run alongside
one another. Playing with --prefix and --exec-prefix in the 2.0.x
configure options comes close, but sharing the runtime directory
hierarchy really tripped me up. Then I thought maybe changing the
$PACKAGE in configure could point the paths to 
/usr/lib/dovecot2,/etc/dovecot2 and so on, but that was an even bigger 
problem (many
directories in the build config are apparently hardcoded to "dovecot/".

So, I just installed 2.0.8 on a separate server and deployed a test user
or two. With good success, I might add, so I don't foresee any issues.
Thanks for your help.