That's exactly what I have done. First moving to dovecot from UW-imap and then switching to Maildir.
What you should know is that UW-imap keep a "beginning of mailbox" message in your mbox. Dovecot doesn't, so all your users will receive a mail like "this is the beginning of your mail folder, don't delete this message". It's quite obvious that there is no risk in deleting it because dovecot doesn't care about this message and shows it as a real message. So your users may be surprised if you don't tell them before the switch.
On my setup, login/pass are from a /etc/passwd, and their mails were kept in /home/username and /var/mail/username, classical with UW-imapd. So I just used this script to convert their mailboxes from mbox to Maildir.
#!/bin/sh
# code by Renaud Allard
mb2md -s /var/mail -d /tmp/Maildir
ls /home | grep -v admin |
while read user
do
mb2md -s /home/$user/mail -d /home/$user/Maildir
rm -rf /home/$user/Maildir/cur /home/$user/Maildir/new /home/$user/Maildir/tmp
mv /tmp/Maildir/.$user/* /home/$user/Maildir
chown -R $user:$user /home/$user/Maildir
done
rm -rf /tmp/Maildir
admins have no mailboxes, hence the "grep -v admin".
I used the Debian package mb2md, but the project is at
http://batleth.sapienti-sat.org/projects/mb2md/
From my tests (not extensively done tough), deleting 1000 mails from a mbox UW-imapd folder (which contained about 3000 mails) took about 1/2h with 100% CPU load on the server (P4 1800, IDE 7200RPM drives). While deleting 1000 mails from a maildir/dovecot setup on the same server takes now about 4sec with no visible CPU load.
PS: Sorry if it comes double-posted because I sent it from a wrong mail address at first time.
On Sun, 17 Jul 2005 05:46:16 +0100
exim-users-request@??? wrote:
> From: Marc Perkel <marc@???>
> To: exim-users@???
> Subject: [exim] Dovecot IMAP - Opinions?
> Date: Sat, 16 Jul 2005 09:23:01 -0700
>
> I've decided to (at least attempting to) convert from a patched version
> of WU-IMAP to Dovecot. The reason I'm choosing Dovecot is because it's
> easiest to convert what I have already to it. I may eventually convert
> to Courier but Courier is poorly documented and it's just too big of a
> step to go from what I have all the way to courier.
>
> Dovecot supports MBOX and Maildir so I can (hopefully) make the
> transition sticking with MBOX, then switch over to Maildir later. Once I
> get that far then I might look at other IMAP servers that are even
> better. I like it that Dovecot doesn't seem to be religious about the
> MBOX vs. Maildir war and I wish Courier supported MBOX if for no other
> reason than making the transision easier. In my case I'm stuck with MBOX
> until I rewrite several other utilities that I currently rely upon.
>
> So - my question. Is there anything scary or weird about Dovecot that I
> should know about or any good resource pages that I should know about?
PGP key:
http://www.llorien.org/gnupg/key.pub
