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@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.

Aki

On 17/12/2020 11:08 Marc Roos <m.roos@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@rfx.it] Sent: 17 December 2020 01:47 To: dovecot@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.

On 17/12/2020 15:38 Barbara M. <barbara@rfx.it> wrote:

On Thu, 17 Dec 2020, Aki Tuomi wrote:

...

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.

Ok, but I assume that dovecot 2.3.x still support mbox? (just in case the mbox --> MailDir migration give more problems than expected expecially with POP3 UIDL)

It's not removed, but we don't focus on maintaining full functionality on it.

Please look at the wiki link on how to use pop3_migration_plugin to avoid UIDL problems.

...

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.

Ok, but My old server is 2.0.16. The suggested URL say: "You need Dovecot v2.1.4+ for this." I can't understand if it refers to source or destination server

I tried to activate master password / master user, but I get:

# telnet 0 143 Trying 0.0.0.0... Connected to 0. Escape character is '^]'.

• OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready. a login USER*MASTER MASTERPWD a NO [AUTHENTICATIONFAILED] Authentication failed.

Nothing in dovecot.[log|info.log]

(real user/pwd replaced) /etc/dovecot/passwd.masterusers created using htpasswd ... tried with standard pwd created by htpasswd or replacing the encrypted pwd with a know passwd form /etc/shadow.

My current dovecot -n :

Try enabling auth_debug=yes

You need to move master passdb before pam. And you need auth_master_user_separator=*

Aki

# 2.0.16: /etc/dovecot/dovecot.conf # OS: Linux 2.6.32-48-pve x86_64 CentOS release 6.10 (Final) auth_mechanisms = plain login default_client_limit = 3000 default_process_limit = 500 disable_plaintext_auth = no info_log_path = /var/log/mail/dovecot.info.log log_path = /var/log/mail/dovecot.log mail_full_filesystem_access = yes mail_location = mbox:~/:INBOX=/var/mail/%u mbox_read_locks = dotlock fcntl passdb { driver = pam } passdb { args = /etc/dovecot/passwd.masterusers driver = passwd-file master = yes pass = yes } protocols = imap pop3 service imap { process_limit = 512 } service pop3 { process_limit = 1024 } ssl_cert = </etc/pki/dovecot/certs/dovecot.pem ssl_cipher_list = ECDHE-RSA-AES256-SHA384:AES256-SHA256:AES256-SHA256:RC4:HIGH:MEDIUM:+TLSv1:+TLSv1.1:+TLSv1.2:!MD5:!ADH:!aNULL:!eNULL:!NULL:!DH:!ADH:!EDH:!AESGCM ssl_key = </etc/pki/dovecot/private/dovecot.pem userdb { driver = passwd } protocol imap { imap_id_log = * } protocol pop3 { pop3_uidl_format = %08Xu%08Xv }

Thanks, B.

I have found opensuse to be very stable and the upgrades to be drama free IF (big if) you stick to the distribution repositories. For a server, sticking to the disty repos is very likely. It is desktop users (me) that load a lot of software from other repos that occasionally muck things up.

I run centos 7 on my servers and opensuse on the desktop. They are very similar. I always have trouble when I have to use Debian, which these days is only on a R Pi. Opensuse can use three different package managers, one of which being yum.

  Original Message  

From: barbara@rfx.it Sent: December 17, 2020 6:57 AM To: dovecot@dovecot.org Subject: RE: migration from 2.0.16

On Thu, 17 Dec 2020, Marc Roos 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. ;)

We own the servers and use CT (LXC). The IBM move is clear, but going to C7 today seems to me not a good choice. It is in its descending stage and in a couple of years packages are going to became very outdated. If RH8 remain "open source" I suppose the community or some interested medium level company that use CentOS for their business can became a new CentOS and switch to a different named distro is supposed to be only a question of replace repositories. That seems to me a smoother path (IMHO). Debian 10 is EOL on 2022 Ubuntu LTS seems a solution, but I hadn't ever used it (I may be wrong, but in the past Canonical don't inspire me to much trust).

Other options (not too "exotic")?

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.

I am studying the situation, but there are many variables and the old age of the source server probably meke it more complex. And I am not a dovecot expert ...

Thanks, B.

Hi,

On Thu, Dec 17, 2020 at 03:56:45PM +0100, Barbara M. wrote:

Debian 10 is EOL on 2022

this may be true, but (1) you can probably expect Debian to have LTS for this - they had for the last few distributions, extending their livetimes to more than 5 years at least (I think Jessie was pulled recently), and upgrades are usually smooth.

Ubuntu LTS seems a solution, but I hadn't ever used it (I may be wrong, but in the past Canonical don't inspire me to much trust).

Me too. IMHO, Debian is the better choice, due to better QA and more effort in backwards compatibility and upgradability. Also, Debian is less driven by commercial considerations, and at least not directly dependend on company policies.

A happy new year all around!

Enjoy, Toni