[Dovecot] Cyrus to Dovecot migration (OS X Server): Backup + restore messages, live "standby server" and delayed expunge and…

[Thomas von Eyben]

Hi List,

I am very close to migrating from Cyrus to Dovecot (to be more precise
from Mac OS X Server 10.5.8 to 10.6.4).
The latter is reporting the dovecotd version to be 1.1.20apple0.5.
All I have read about dovecot is extremely positive so I am exited to
make the switch.


BACKUP:
BUT I would like to be sure that I can make a sound backup strategy.
For Cyrus i used topicdesk's mailbfr (a script that stops the
mailservice and then rsync's the mailstore to a backup location
incrementing daily and restarting a complete backup weekly).

This script is not yet ready for Dovecot, but from what I have read it
should be as easy as "just" backing up the mail-data
(/var/spool/imap/dovecot/mail in OS X), eg. with rsync.

Our current setup is requiring ca. 11 hours for a full (200+ GB)
backup (weekly) this is not good for uptime…


RESTORE:
Restore should be the same (well reverse) "just" restoring the files
and making sure the get the correct permissions.
What I am not sure about is the (cyrus specific) need for
reconstructing the database, as I have read (on this list) it seems
that dovecot is designed better and will "automatically" recognised
the restored messages without the need to reconstruct any databases or
stopping+restarting the service.
Is this really true ,-)?
NB.: For restores I plan to always restore to a specific subfolder for
the user (eg RESTORED MAIL) as opposed to placing the mails within the
folder hierachy



LIVE BACKUP SERVER
I have been told, that dovecot provides clever mechanisms for making
it possible to synchronise the data to a "hot-spare" server. Both for
being able to provide access to the data during breakdown or planned
maintenance, but perhaps also to make backups easier (perhaps not
needed?)



DELAYED DELETION OF MESSAGES
I believe that the feature is called "delayed expunge", a way of not
deleting the messages until after an additional delay from the time
the user deletes the message. Is this possible in dovecot?



DOCUMENTATION
Where would the best FAQ/KB for getting to know dovecot better be,
perhaps there have even been written good books (I know old fashioned,
but I really like the physical hands on a real book provides ;-)

It's a lot of questions and I hope for good pointers to where I can
find more documentation and good feedback from the list.


BR Thomas von Eyben