migration with doveadm backup to new cluster running dovecot 2.2.36 and replicator

[Thomas Winterstein]

>> dsync is intended to be used to change mailbox format, so it should work just fine.

that's exactly what we thought and why we use dsync to migrate like 
described here

   https://wiki2.dovecot.org/Migration/Dsync


Our replication is configured according to

   https://wiki.dovecot.org/Replication


Both processes run separately in time.


Still on some accounts mails of Inbox or another folder get duplicated. 
We're currently trying to debug this.

what are we missing?

thanks
Thomas

On 07.01.2021 10:21, Aki Tuomi wrote:
> dsync is intended to be used to change mailbox format, so it should work just fine.
> 
> Aki
> 
>> On 07/01/2021 11:17 Andrea Gabellini <andrea.gabellini at telecomitalia.sm> wrote:
>>
>>   
>> Hello,
>>
>> I had a similar problem some time ago, and the problem was the mailbox
>> format change.
>>
>> Please try to migrate with the same format.
>>
>> Andrea
>>
>> Il 05/01/21 15:02, Thomas Winterstein ha scritto:
>>> No one?
>>>
>>> If there are limitations in regards to how dsync in migration and
>>> replication can operate together these should be stated clearly in the
>>> documentation.
>>>
>>> On 23.12.2020 20:33, Thomas Winterstein wrote:
>>>> Hello everyone,
>>>>
>>>>
>>>> we are working on migrating from dovecot 2.0.9 (maildir) to 2.2.36
>>>> (mdbox). The new cluster has two backend mail servers which replicate
>>>> through doveadm replicator. To move the data initially we use doveadm
>>>> backup (imapc).
>>>>
>>>> arb
>>>> Our migration command
>>>>    doveadm -o mail_fsync=never backup -R -u $user imapc:
>>>>
>>>>
>>>> To test the replication of new and purge of old mails with live data
>>>> changes we ran imapc on a daily basis but encountered the problem
>>>> that some mailboxes multiplied in size. We then made sure that imapc
>>>> and replication don't run at the same time but after the first
>>>> incremental imapc process, we still had the same problems.
>>>>
>>>>
>>>> The doveadm-backup man-page states that it's possible to run it
>>>> multiple times during migration. But is it also possible to have the
>>>> replicator running in between? From our understanding the doveadm
>>>> backup should just work as an imap connection between the servers,
>>>> synchronizing all changes made on the source to the destination. Or
>>>> does the conversion from maildir to mdbox format in our case produce
>>>> the problems?
>>>>
>>>>
>>>> If you're not supposed to run the replicator before having fully
>>>> migrated, how can we shorten the downtime? rsync? And how can we be
>>>> sure that similar problems don't occur after the migration if we
>>>> can't test all mechanisms together with live data?
>>>>
>>>>
>>>> thanks
>>>
>>>
>>
>> -- 
>> __________________________
>> Daddy, why doesn't this magnet pick up this floppy ?
>> __________________________
>>
>> TIM San Marino S.p.A.
>> Andrea Gabellini
>> Engineering R&D
>> TIM San Marino S.p.A. - https://www.telecomitalia.sm
>> Via Ventotto Luglio, 212 - Piano -2
>> 47893 - Borgo Maggiore - Republic of San Marino
>> Tel: (+378) 0549 886237
>> Fax: (+378) 0549 886188
>>
>>
>> --
>> Informativa Privacy
>>
>> Questa email ha per destinatari dei contatti presenti negli archivi di TIM San Marino S.p.A.. Tutte le informazioni vengono trattate e tutelate nel rispetto della normativa vigente sulla protezione dei dati personali (Reg. EU 2016/679). Per richiedere informazioni e/o variazioni e/o la cancellazione dei vostri dati presenti nei nostri archivi potete inviare una email a privacy at telecomitalia.sm.
>>
>> Avviso di Riservatezza
>>
>> Il contenuto di questa e-mail e degli eventuali allegati e' strettamente confidenziale e destinato alla/e persona/e a cui e' indirizzato. Se avete ricevuto per errore questa e-mail, vi preghiamo di segnalarcelo immediatamente e di cancellarla dal vostro computer. E' fatto divieto di copiare e divulgare il contenuto di questa e-mail. Ogni utilizzo abusivo delle informazioni qui contenute da parte di persone terze o comunque non indicate nella presente e-mail potra' essere perseguito ai sensi di legge.


-- 
Thomas Winterstein .................... http://www.rz.uni-augsburg.de/
Universität Augsburg, Rechenzentrum ............. Tel. (0821) 598-2068
86135 Augsburg .................................. Fax. (0821) 598-2028