[Dovecot] Live Mirror dovecot / OS X 10.6.4 (Timo Sirainen)

[Eric Boltz (MMI/UPC)]

On Aug 25, 2010, at 10:15 AM, Timo Sirainen wrote:
> 
> But if secondary server allowed changes, this is the difficult step to
> do correctly. For example lets say in first server:
> 
> 1. It rsyncs user foo
> 2. User foo changes message A flag to \Seen
> 3. User foo deletes message B
> 4. User foo saves a new message C
> 5. The server crashes
> 6. Secondary server goes up, but 2-4 changes weren't resynced yet
> 7. User foo logs in and changes message D's flag to \Seen
> 8. Primary server goes back up
> 9. You rsync .. how? If you make primary server look exactly like
> secondary server, you message C gets lost. If you copy new files, now
> message A and message D gets duplicated, because their filename changed
> due to the flag change. Also message B becomes undeleted.
> 
> Of course assuming this happens rarely enough, those aren't a huge
> problem, but the server move isn't always transparent to users and
> you'll get errors in Dovecot's logs.

First off, thanks.
It will happen rarely (2-3x/year most likely base on prior power outages) and if a couple users get a duplicate message or unread when read issue they can file a complaint :)
The transfer wouldn't be transparent - I would force them to webmail on the backup (maybe even force POP3?).

Now to figure out where the virtual user data is...sigh