Migration

[Ignacio García]

A totally different approach (that is imap-server agnostic), providing 
that you're setting up those new accounts with temporary passwords 
(which you know), before users change their passwords to their liking: 
you could also use imapsync ( https://github.com/imapsync/imapsync) . We 
here use it with a batch file and a text file containing all accounts to 
do mass-migrations, usually at night, when there's little to none user 
interaction with their mail accounts. I like this approach because mail 
service never gets interrupted and we do programmed syncs all night in 
case DNS propagation takes more than expected and mail still arrives to 
the old server.

Ignacio


El 30/12/2018 a las 23:09, Hans Brage escribió:
> Thanks!
>
> That was a really useful answer.
>
> // Hans
>
>
> Den 2018-12-30 kl. 10:53, skrev Sami Ketola:
>>> On 29 Dec 2018, at 23.49, Hans Brage <hans at plattformen.se> wrote:
>>>
>>> Hi!
>>>
>>> I'm currently running an small imap-server on Dovecot 2.2.4 but will 
>>> retire that server. I've set up an new server with Dovecot 2.3.4 and 
>>> will migrate the mailboxes (maildir-format) from the old to the new 
>>> server. I'm planning to restructure the accounts a bit when 
>>> migrating so I need to move them one by one. Its only a few so thats 
>>> not a big issue.
>>>
>>> Both servers are using virtual accounts (users file).
>>>
>>> I've understood that best method for migration is to run doveadm 
>>> backup -R from the new server. But I really cant figure out what 
>>> other parameters or settings that I need to perform that task and if 
>>> it should be run as user vmail or root.
>>>
>>> Would be greatful for any tips, hints, links or similiar.
>>
>> Once you have the new server set up, you can use dsync over ssh to 
>> sync the mailboxes with something like:
>>
>> doveadm backup -u user at newserver -R ssh sudouser at oldserver sudo 
>> /usr/bin/doveadm dsync-server -u user at oldserver
>>
>> needs to be run as root on new server. Also ssh access with keys and 
>> without password is recommended.
>>
>> Sami
>>
>>