migration from 2.0.16

Aki Tuomi aki.tuomi at open-xchange.com
Thu Dec 17 11:16:00 EET 2020

I would recommend using dsync migration to get rid of mbox format. We no longer develop that format, and bugs are limited to reading mbox format.

I would also recommend using master password / master user login with doveadm sync, and do the synchronization over imapc: to get the data safely migrated to your new system.

You should use

doveadm sync -u user backup -R imapc:

on the new server to pull the data from old server. See https://wiki.dovecot.org/Migration/Dsync for more details.


> On 17/12/2020 11:08 Marc Roos <m.roos at f1-outsourcing.eu> wrote:
> I would not choose centos 8 it has EOL < than centos7. IBM is pulling 
> the plug on the centos distribution, and makes it more or less a beta 
> for the rhel. Thus centos7 and then you have a few years to decide what 
> to choose. Enough to go to full containerized eg. ;)
> You do not need to rsync, dovecot can sync messages. I am just in the 
> process of migrating a server from a different network to a different 
> mailbox format. 
> My approach was to create an 'archive' namespace on shared slower but 
> distributed storage so I do not have to move to much data.
> -----Original Message-----
> From: Barbara M. [mailto:barbara at rfx.it] 
> Sent: 17 December 2020 01:47
> To: dovecot at dovecot.org
> Subject: migration from 2.0.16
> I have an old server with CentOS 6.x and dovecot 2.0.16 (postfix-2.6.6 
> and roundcube), that was an update from a 1.x many years ago ...
> Users in /etc/passwd
> Mailbox format mbox
> some filtering via procmail
> About 5.000 users, 1 TB data (/var/mail + /home/users)
> Obviously I am searching for a smooth upgrade path (with no or minimal 
> downtime and users problems) ;-)
> Until few days ago my idea was a CentOS 8.x new box with the standard 
> default packages (dovecot-2.3.8, postfix-3.3, ...).
> Now this can be reconsidered. I suppose there will be a RockyLinux or 
> something equivalent but if there is a good reason I can consider Debian 
> or other OS if they have a decent EOL or some advantages.
> Anyway, the more relevant problem at the moment is collect info for the 
> best approch to have a smooth dovecot upgrade.
> My dream is the possibility to configure a new server and rsync the data 
> (/var/mail + /home/users), and, when the tests are satisfiable do the 
> final sync and swap the IP, but I suppose deleting the .imap folders 
> isn't a simple complete solution to compatibility problems.
> Any hints, links, experiences are appreciated.
> Thanks, B.

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