I've been migrating from a dovecot 2.2.22 instance to a dovecot 2.3.7.2 instance. (Said differently, from an ubuntu 16.04 host to a 20.04 host.) It's a tiny site: only a handful of users actually had to migrate, most either died on the old one or were born on the new one. The main user in need of migration was me.
After fiddling with dsync and not getting it working, I threw in the towel. This is a migration I had to do once for precisely one user. I had been using the old host exclusively, so it was easy to shut down both dovecot instances the time it took me to rsync my data from one to the other. Now that seems to work, almost. Mail is being delivered to my inbox, anyway. Most other folders are looking inaccessible to my mail client (thunderbird, for this test).
The main difference between the two servers, aside from the above, is a switch from
mail_location = maildir:~/Maildir
to
mail_home = /var/mail/vmail/%d/%n mail_location = maildir:/var/mail/vmail/%d/%n/mail:LAYOUT=fs mail_privileged_group = mail
I corrected permissions and ownership when I copied the data.
Now I think the problem is that LAYOUT=fs means that I should have a slightly different folder hierarchy now. The question is how best to fix this.
I have things like this
.Archives.2020 .Archives.2020/new .Archives.2020/tmp .Archives.2020/cur
when I think I should have things like this
Archives Archives/2021 Archives/2021/new Archives/2021/tmp Archives/2021/cur
And, again, this is one-off, so a manual fix seems most appropriate. I'm quite tempted simply to shut down the dovecot instance for a minute at a quiet moment (mail retries...) and rename directories as indicated above. I only have to rename five directories.
Having gotten myself in a bit of a muddle on this, I thought perhaps a reality check that I'm not about to make it worse would be appropriate.
Many thanks.
-- Jeff Abrahamson +33 6 24 40 01 57 +44 7920 594 255 https://www.p27.eu/jeff/ https://www.mobilitains.fr/