Migrating from 2.0.x to 2.2

[Michael Grimm]

On 2014-09-05 11:54, Jens Dueholm Christensen wrote:

> Filesystems are prepared for the expected amount of inodes required,
> and for the time beeing a change to mdbox is seen as an added
> complexity.

With that amount of mails in mind, a migration to mdbox is a good idea, 
IMHO.

> One requirement of the migration is that messageID is not changed -
> mails are referenced by other systems that expect to find individual
> mails by the ID.
> 
> Since dsync is incompatible between 2.0<->2.1<->2.2 what is the best
> way to perform this migration?

IIRC dsync can be run independently from a running dovecot server. If 
that is correct, then you could install dovecot 2.2 at the old server, 
and use that dsync 2.2 for migration to the new server by simultaneously 
changing the mail storage format. Again, IIRC, all your message IDs 
shouldn't be modified during that approach.

Just give it a try ;-)

Regards,
Michael