[Dovecot] Best way to migrate versions and machines

[Ed W]

On 17/02/2011 15:29, Donny Brooks wrote:
> We are looking to migrate from our current mail server running 
> dovecot-1.2.11-3 to a new mail server running the latest dovecot 
> (2.0.9?). So this would not only be a version change but also a 
> machine change. We currently use Maildir for storing mail and would 
> like to stay that way.
>
> Has anyone preformed such a feat and it worked? Looking for any input.
>

I have had a lot of success in setting up both Dovecot and Postfix to 
read a "mail_location" field which points to the IP of the users real 
mail server.  When this changes then another dovecot instance proxies to 
the correct machine and postfix invokes a transport map to shift the 
mail to the correct machine (I think Dovecot has a %my_IP variable and 
also you can kind of extract your IP at the mysql server side, where you 
need this param in a query)

In this way you can easily move individual users around very simply.  
Your migration can then also be just a few users at first, more through 
time, rather than a big bang approach

If your question was migrating config then I think I would start with 
the default new config and migrate your old changes across.  Also run 
the config upgrade on the old config.  Now compare the results of both 
methods and see if this helps you spot anything you missed during your 
manual migration?  Apart from config changes, I think the upgrade is 
likely to be uneventful?

Good luck

Ed W