[Dovecot] IMAP to Maildir Migration preserving UIDs?

[Gedalya]

On 01/26/2012 07:27 AM, Timo Sirainen wrote:
> On 26.1.2012, at 6.31, Gedalya wrote:
>
>> I'm facing the need to migrate from a proprietary IMAP server to Dovecot. The migration must be as smooth and transparent as possible.
>>
>> The mailbox format I would want to use is Maildir++.
>>
>> The storage format used by the current server is unknown, and I don't look forward to trying to reverse-engineer it. This leaves me with the option of reading the mailboxes using IMAP. There are tools like offlineimap or mbsync, and they do store the UID and UIDVALIDITY info. The last piece of the puzzle is a process to properly create the dovecot-uidlist and dovecot-uidvalidity files. So far I wasn't able to find anything on this. Are there any tips? Are there any tools available to do this job, or part of it?
> Get Dovecot v2.1 and configure it to work. Then for migration add to dovecot.conf:
>
> imapc_host = imap.example.com
> imapc_port = 993
> imapc_ssl = imaps
> imapc_ssl_ca_dir = /etc/ssl/certs
> mail_prefetch_count = 50
>
> And do the migration one user at a time:
>
> doveadm -o imapc_user=USERNAME -o imapc_password=PASSWORD backup -R imapc:
>
Still working on it on my side, but for now:

# doveadm -o imapc_user=gedalya at thisdomain.com -o imapc_password=***** 
backup -u gedalya at thisdomain.com -R imapc:
Segmentation fault


syslog:

Jan 26 18:34:29 imap01 kernel: [ 9055.766548] doveadm[8015]: segfault at 
4 ip b7765752 sp bff90600 error 4 in 
libdovecot-storage.so.0.0.0[b769a000+ff000]
Jan 26 18:34:53 imap01 kernel: [ 9078.883024] doveadm[8046]: segfault at 
4 ip b7828752 sp bf964450 error 4 in 
libdovecot-storage.so.0.0.0[b775d000+ff000]

(I tried twice)

Also, I happen to have no idea what I'm doing, but still, segfault..

This is a debian testing "wheezy" machine I put up to do the initial 
playing around, i386, using Dovecot prebuilt binary packages from 
http://xi.rename-it.nl/debian/pool/testing-auto/dovecot-2.1/