Best way to move mail from one server to another

[Alex La]

Hi Robert.

Am 06.09.18 um 08:50 schrieb Robert Schetterer:
> Am 05.09.2018 um 07:37 schrieb Aki Tuomi:
>>
>>> On 04 September 2018 at 23:20 Robert Schetterer <rs at sys4.de> wrote:
>>>
>>>
>>> Am 04.09.2018 um 18:27 schrieb Sami Ketola:
>>>>
>>>>
>>>>> On 4 Sep 2018, at 18.38, Robert Schetterer <rs at sys4.de> wrote:
>>>>>
>>>>> Sorry i migrated terrabytes of mail with imapsync and never had a
>>>>> problem, it works as designed, also with maildir rsync did a good job,
>>>>> what never worked as it should was dsync ,cause of bugs ,that may
>>>>> changed now
>>>>>
>>>>
>>>> I would like to very much hear about the problems you had with dsync as we
>>>> have successfully migrated tens of petabytes of mails with it successfully
>>>> while preserving the UID numbers.
>>>> Imapsync would have been totally out of question as it is absolutely crucial
>>>> in those migrations to keep the UID -> MAIL pairs matching legacy server.
>>>> And usually also POP3 UIDLs. If not keeping the data the servers would have
>>>> literally melted under load when switching over then of thousands of users
>>>> forcing them to redownload headers of even mail bodies for millions of mails.
>>>>
>>>> Sami
>>>>
>>>>
>>>
>>> I think you should know the dove buglist, i used dovecot since the beginning
>>> and believe me dsync had a lot of problems, as i stated i hope this had
>>> changed now. I didnt used/tested it again the last years cause i had no
>>> big migration job to do, we ever tried to use it that days cause youre
>>> right we would have prefer not broke pop3 stuff at migration. But it
>>> never worked, so imapsync was the best way to go, also having courier,
>>> cyrus migrations with format/namespace change etc.
>>>
>>> Imapsync works as designed and migration might not be ideal at some
>>> points but it has no real stoppers if migration is well prepared and
>>> organized.
>>>
>>>
>>> Best Regards
>>> MfG Robert Schetterer
>>
>> There has been progress with dsync in the past years, and it can do courier
>> and cyrus migrations with format/namespace changes. "Few years ago" is a long
>> time.
> 
> we will give a retry end of this year and report

What's your opinion now for `doveadm backup/sync ...`?

>>
>> Aki
>>>
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