migration from 2.0.16

Marc Roos M.Roos at f1-outsourcing.eu
Thu Dec 17 11:26:31 EET 2020

Oh interesting this imapc option. Is there any advantage of using that 
instead of what I am currently using 
doveadm  backup -n inbox -F /root/backup-rest-2.txt tcp:mail04.local:542

Also any difference between pulling or pushing the messages? To check, I 
have made some script that outputs messages of mailboxes that I can 
compare between source and destination server. But this of course does 
not show if messages are 100% ok.

[@ ~]# mailbox-ls.sh test size
listing mailboxes of test:
Archive messages=0
Archive/2011 messages=0
Archive/2012 messages=0
Archive/2013 messages=0
Archive/2014 messages=0
Archive/2015 messages=0
Archive/2016 messages=0
Archive/2017 messages=0
Archive/2018 messages=0
Archive/2019 messages=3500
Archive/Archive messages=1
Deleted Messages messages=28
Drafts messages=2
INBOX messages=1325
INBOX/test2 messages=3
Junk messages=2
Sent messages=1
Trash messages=132

-----Original Message-----
From: Aki Tuomi [mailto:aki.tuomi at open-xchange.com] 
Sent: 17 December 2020 10:16
To: Marc Roos; barbara; dovecot
Subject: RE: migration from 2.0.16

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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