W/o downtime: see the wiki page below, the "Converting" section.
Briefly for my case something like this should work and generally seems
simple (no syntax checking yet, pseudo-code like):
* Configuration uses mail_location = mbox:~/mails
* setup per-user mail location and do for each user individually in a
serial manner:
-- doveadm sync maildir:~/Maildir; mbox is synced to Maildir, long
running time
-- doveadm sync maildir:~/Maildir; rerun to do it for new messages (fast)
-- add USER to userdb and set extra field to maildir:~/Maildir
users not present in the userdb should default to dovcot default;
conditionally optional: doveadm auth cache flush
-- doveadm kick (to force clients of USER to use the new Maildir)
-- doveadm sync -R mbox:~/mails (rerun to sync the very last few mails,
which arrived during the editing and reloading the userdb config)
* when done for all users, I set maildir:~/Maildir for mail location and
remove the userdb file definition
The problem of postfix/procmail:
* I found this, but I do not prefer edit procmail config this way
http://dmc1961.id.au/howto_17101101.php
* I think that dovecot/lmpt is a better solution:
-- dovecot takes care of the delivery and it will also know where to
deliver during the mixed situation
-- on the long term: told to have better performance compared to
procmail; https://wiki2.dovecot.org/HowTo/PostfixDovecotLMTP
On 2019. 01. 29. 19:49, Marc Roos wrote:>
> I am also migration away from mbox to in my case mdbox. I am not fully
> aware of something that allows you to do this without downtime.
>
> To try to do as much as possible online, I have created an archive
> namespace and am moving the larger >5GB mbox files with old emails to
> that. So when the time is there to do convert active mailboxes, I have
> less to convert. Maybe this is helpful.
>
>
>
>
> -----Original Message-----
> From: Tamas Hegedus [mailto:tamas at hegelab.org]
> Sent: 29 January 2019 17:39
> To: dovecot at dovecot.org
> Subject: mbox 2 Maildir
>
> Hi,
>
> I am not an professional system admin, but I am running a small debian
> mail server for many years. It is time to migrate from mbox to Maildir.
> There is a nice and clean description for doing this without service
> downtime at https://wiki.dovecot.org/Tools/Doveadm/Sync
> I have to set per-user config for mailbox type using userdb extra
> fields.
>
> However, I miss some information and I can not find useful info by
> google.
>
> 1. The main question: dovecot will know that for some users the mailbox
> format is still mbox, but others already have Maildir. I do not see any
> hint that I should setup postfix/procmail for handling the delivery
> per-user basis. But I think I have to set this, too.
>
> 2. I have not learned much about userdb and it seems that dovecot was
> written for and used by experts. I mean that the docs/wiki is not enough
> for me: from the wiki page of userdb it will be for me difficult to
> setup one. Can you suggest some docs for dummies?
>
> Thanks for your help, Tamas
>
> dovecot --version 2.2.27 (c0f36b0)
> postfix 3.1.8
> procmail v3.23pre 2001/09/13
>
> --
> Tamas Hegedus, PhD
> Senior Research Fellow
> MTA-SE Molecular Biophysics Research Group Hungarian Academy of Sciences
> | phone: (36) 1-459 1500/60233
> Semmelweis University | fax: (36) 1-266 6656
> Tuzolto utca 37-47 | mailto:tamas at hegelab.org
> Budapest, 1094, Hungary | http://www.hegelab.org
>
> ---
> This email has been checked for viruses by AVG.
> https://www.avg.com
>
>
>
--
Tamas Hegedus, PhD
Senior Research Fellow
MTA-SE Molecular Biophysics Research Group
Hungarian Academy of Sciences | phone: (36) 1-459 1500/60233
Semmelweis University | fax: (36) 1-266 6656
Tuzolto utca 37-47 | mailto:tamas at hegelab.org
Budapest, 1094, Hungary | http://www.hegelab.org