[Dovecot] dsync Migration Couldn't keep all uids dove 2.1.16

[Robert Schetterer]

Am 22.05.2013 19:03, schrieb Timo Sirainen:
> On 22.5.2013, at 15.56, Robert Schetterer <rs at sys4.de> wrote:
> 
>> Am 22.05.2013 13:36, schrieb Robert Schetterer:
>>> Am 22.05.2013 10:32, schrieb Robert Schetterer:
>>>> Hi Timo, using
>>>>
>>>> http://wiki2.dovecot.org/Migration/Dsync
>>>>
>>>> for migration
>>>>
>>>> i am getting this in periods
>>>>
>>>> dsync(sys4-test-2 at example.de): Info: INBOX: Couldn't keep all uids
> 
> Did the destination server maybe already get some new mails?
> 
>>>> dsync(sys4-test-2 at example.de): Warning: Mailbox changes caused a desync.
>>>> You may want to run dsync again.
> 
> Does this help?

no, run again dsync , does not fix the expunge problem

> 
>>> sorry for noise , i did more testing, guess the general problem
>>> is in missing read
>>>
>>> Problems
>>>
>>>    POP3 message order (when it's different from IMAP message order) is
>>> currently preserved only when destination is Maildir
> 
> This doesn't break dsync in any way, it just means that POP3 clients will see the UIDL list in different order then they used to, which will probably cause them to redownload mails. I already implemented the ordering support for dbox, but the ordering then also needs to be added to dovecot.index.cache, and that's causing some problems, so I haven't committed the change yet..
> 
>> more tests showed up, that expunged mails arent synced anyway whatever
>> mailbox format is used
>>
>> perhaps that problem ?
> 
> The source is IMAP+POP3 server? Yeah, could be that it's not handling expunges when doing dsync the second time. v2.2 should be handling them better I think, although I haven't really tested much yet.

Hi Timo,
it looks like a problem with dsync migration in 2.1.16, with "that"
source server, a friend reported dsync migration form cyrus to sdbox had
worked fine with 2.1.15

> 
>> If source POP3 server merges multiple IMAP mailboxes into one POP3
>> INBOX, the migration won't be transparent.
>> If source IMAP and POP3 servers return messages somehow differently,
>> pop3-migration plugin might not be able to match the messages
>>
>> how test this on source server i dont see something special there using
>> telnet and/or Thunderbird
> 
> That is about if the same messages exist in POP3 session and IMAP INBOX. Just checking if their counts are equivalent is pretty much enough alone. In any case even if that happened, it doesn't cause your dsync problems.
> 

i think i wont invest more time in this, dsync has/will much changed
code in 2.2.x , so i may retest again with 2.2.x sometime, meanwhile for
this case i might use imapsync, but thx for repeat anyway

however in case i would discover any more big news with dsnyc migration
2.1.16 , i will report

Best Regards
MfG Robert Schetterer

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