[Dovecot] Cyrus to Dovecot migration (OS X Server): Backup + restore messages, live "standby server" and delayed expunge and…
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
On 05/08/2010 10:28, Thomas von Eyben wrote:
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).
Just a tip, but during my migration I first switched all users to point at dovecot, but used the "proxy" feature to point them back to the original mail server. This allowed me to migrate across just one user at a time and check for problems until I have all users migrated onto Dovecot.
This doesn't help you with the other stuff, but it may give you a soft way to migrate a bit more slowly than a big bang?
Good luck
Ed W
On Thu, 2010-08-05 at 11:28 +0200, Thomas von Eyben wrote:
RESTORE: 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 ,-)?
Yes.
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?
There's a lazy_expunge plugin: http://wiki.dovecot.org/Plugins/Lazyexpunge
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 ;-)
There's the wiki of course, but other than that I don't know really. I'm not aware of any Dovecot books (although one is being started I think).
participants (3)
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Ed W
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Thomas von Eyben
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Timo Sirainen