[Dovecot] Re: 0.99.10.5 release candidate

[Christian Balzer]

Brian wrote:
>On Mon, May 31, 2004 at 07:24:41PM +0300, Timo Sirainen wrote:
>> >   -ERR This message has been deleted by someone else!
>> > 
>> > or something like that. I can live with that.
>> 
>> That's what Dovecot does now.
>> 
>> But that isn't the worst if you have no locks at all. You still want to
>> lock the mailbox while it's being read or written, otherwise there would
>> be either mailbox corruption (two writers at the same time) or user
>> could be sent corrupted mails (one reading while another is writing).
>
>Oh yes, sorry. I now think "Maildir" exclusively, and forget that some
>people still use mbox :-)
>
Converting tens of thousands of users (in a fast and transparent as 
possible fashion) is no easy feat.

>Having seen mailservers where users leave 10-20MB of mail on the server, in
>a single mbox file, where the POP3 server has to read through the whole mbox
>every time they login just to count how many messages are in there... well,
>that's enough for me to give up on mbox.
>
Tell me about it. ;P

Note though that maildir still leaves you vulnerable to some extent 
with large individual mails (we allow for 10MB per message max here). 
The atomic tmp -> new move prevents of course the case of multiple 
(inbound, SMTP) writers. Alas following a recent conversation in this
ML with Timo all that saves your butt and mail integrity in the case
when a large message being read by slow client gets deleted by another
client (dovecot instance) is Saint BufferCache. ;)

Regards,

Christian
-- 
Christian Balzer        Network/Systems Engineer                NOC
chibi at gol.com   	Global OnLine Japan/Fusion Network Services
http://www.gol.com/