[Mailsync-list] Migrating cyrus imap Suse Emailserver 3 to Debian/testing

[Sascha W. <bi...@ki...>]

Hi mailsync-list members,

I am to migrate a running emailserver "Suse Emailserver 3" shipped with
cyrus-imapd v2.0.16 to an up-to-date debian/testing with cyrus21-*
v2.1.16. The new system shall replace the old and shall have all
mailboxes containing full content and also all shared folders with full
content - seen-information shall be original of all content, too. The
emailusers shall notice no difference in use to the change.

The new debian emailserver is ready tested to take the old messages.

I have access to both email servers and backupserver filesystems, and I 
am ordered not to stress the running server. So I'd like to use mailsync
migrating from a local directory containing the old emailservers
files.

My worries are, that the folder structure of old and new cyrus are so
different.
- Does mailsync care for it and places everything to the right
  _new_version_ place? See downwards for a description.

I have not yet read the mailsync documentation carefully, because I am
in a hurry and very limited with time. Testing is complicated because of
limited bandwith and huge amount of data, so I'd like to ask you more
questions:

Assuming above answer of my question is yes:
- If I use a complete backup of all data to migrate residing in a local
  directory, can I use mailsync to sync /old-directory to the current
  system regarding all mailboxes, shared folders and seen information
  with one single command?
- I want to test the result of mailsync with a not up-to-date snapshot
  just to make shure that everything will be alright and step back
  afterwards and use the current data if I trust it. I assume just
  deleting the corresponding directories of cyrus ( /var/spool/cyrus, 
  /var/lib/cyrus) and restoring from a local backup of the situation
  before would be sufficient, right? mailsync does not touch /etc or so,
  does it?
- Which directories of the old data must be in place if using from a
  local directory?

Let me list information about the folder structure of old and new cyrus:

old:
/var/spool/imap contains a lot shared folders, user and stage.
/var/spool/imap/user contains folders with the mailusers name but no
single letter directories - the mailusers name folders are the mailboxes
/var/imap contains the working directory of cyrus, e.g mailboxes-db

new:
/var/spool/cyrus/mail contains directories from a-z and stage.
At the single letter directories you find user/ and mailusers name
folders therein, e.g.
/var/spool/cyrus/mail/s/user/sascha - this is the testuser's mailbox
/var/lib/cyrus is cyrus' working directory

...if mailsync is not capable to do what I am expected to get ready -
does anybody know a source of tools which can migrate the structure of
cyrus v2.0.16 to v2.1.16?

Thanks so far for reading.

greetings,
Sascha