[Dovecot] dsync migration questions

[Timo Sirainen]

On 14.3.2013, at 21.07, Michael Smith (DF) <msmith at datafoundry.com> wrote:

> dsync -D -v -R -u anakin at domain.com backup mbox:/mnt/mail/mail_spool/.migrate/
..
> dsync(anakin): Error: Trying to open a non-listed mailbox with guid=814b6332541c425169490000a72406a4
> dsync(anakin): Error: msg iteration failed: Couldn't open mailbox 814b6332541c425169490000a72406a4
> dsync(anakin): Error: Trying to open a non-listed mailbox with guid=814b6332541c425169490000a72406a4
> 
> Nothing was migrated.  In some other combinations, trying to reproduce them again, it does migrate the old mail, but first destroys the existing mail in the new mailbox.

Use doveadm sync (= dsync mirror) instead of backup.

> Our goal is to cut mail delivery over to the new dovecot system (which will result in existing emails before migration), and then migrate the old mail *while* maintaining message UIDs.  This is the easiest way to ensure no "lost" email with the migration.
> 
> What are we doing wrong, and how do we achieve our goals?

Looks like a dsync bug. v2.2 has much better dsync with clearer errors.