On 17.2.2013, at 12.19, Michael Grimm <trash...@odo.in-berlin.de> wrote:
> On 17.02.2013, at 11:08, Timo Sirainen <t...@iki.fi> wrote: >> On Sun, 2013-02-17 at 10:44 +0100, Michael Grimm wrote: > >>>> Although even if it does, other parts of Dovecot still use only the >>>> hostname part to guarantee global uniqueness of things. So better to have >>>> unique hostnames. >>> >>> What parts of Dovecot would be involved? I'm curious because my production >>> mailservers use identical hostnames in their jails ever since running >>> Dovecot (starting 1.x). >> >> Mainly that maildir filenames are used as GUIDs. If two have the same >> name, they are assumed to be identical. That's why the maildir filenames >> include the hostname in them, to make sure that the GUID is different >> even if two mails happen to be delivered at exactly the same time with >> the same PID and same size to two different servers. So pretty unlikely, >> but better to be safe. :) > > Ok, that won't hit me for the time being because I am using mdbox. It's basically the same with mdbox, except instead of using actual hostname it's using a 32bit hash of it. (So yeah, ideally there should be checks for detecting hostname hash collisions..)
