migration from 2.0.16

[Marc Roos]

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.