[Dovecot] Best way to migrate from Qpopper to Dovecot

[Torsten]

Hi David,

we did nearly the same procedure the last time we switched from an old 
Qpopper maschine to a new Qpopper maschine.
The last time we had not so much users (maybe 16000), not so much data 
(round about 20Gigs) and there was no need of conversion.
This time we have new DNS-Names, new environment (Dovecot) and so on.

So David, may I ask you how long did it take to convert the data?

Thanks
Torsten


David Robillard schrieb:
> Hello Torsten,
>
> We switched our 3500+ users from Qpopper to Dovecot last week-end. We
> had around 27Gb of data to migrate. We had a maintenance window in
> which we could stop the POP services, so it was quite easy to do. Even
> if we changed hardware, we kept the old name and IP so that we had no
> DNS changes to do. Clean and simple.
>
> Here's how we've done things on FreeBSD 6.2-RELEASE-p2
>
> -- Shutdown qpopper POP services on the old machine.
> -- Create a tar and transfered it to the new machine. Acutally, this
> was a single step in which we used a pipe to send that tar STDOUT into
> ssh's STDIN.
> -- Import /etc/master.passwd and /etc/group from the old system into
> the new machine.
> -- Run a simple shell script to change from mbox format to Maildir
> using mb2md and set permissions.
> -- Exchange FQDN and IP between to old machine and the new one in
> order to prevent any DNS changes.
> -- Start Dovecot and your MTA on the new machine.
>
> Concerning your desire to move your user's Maildir into
> /var/mail/first_letter_of_username/username. It should be trivial to
> do using a simple /bin/sh script.
>
> Have fun !
>
> David