[Dovecot] Director (was: Hints for a NFS-Setup)

[Timo Sirainen]

On 6.4.2012, at 16.58, Patrick Westenberg wrote:

> Hi again,
> 
> I tried to setup a test invironemnt like this:
> 
> MTA --(lmtp)--\               /--(lmtp)--> backend1 --\
>                -- director --                         -- NFS
> MTA --(lmtp)--/               \--(lmtp)--> backend2 --/
> 
> 
> IMAP-User --> frontend1 --\              /--(imap)--> backend1 --\
>                           -- director --                         -- NFS
> IMAP-User --> frontend2 --/              \--(imap)--> backend2 --/
> 
> but now I'm very confused. Is it actually possible to setup a host (or two) as a director only or will I have to enable the director service on each frontend and MTA?

The cleanest way to run director is to have 2 or more servers running only director itself. If you want to have less servers, it's also possible to place a Dovecot director configuration to any other servers as well, but that's conceptually more complex.

For MTA you'd simply tell its LMTP client to connect to director servers, which could be one of:

a) Load balancer's IP address

b) Host name that expands to all directors' IP addresses. If the first one is down, the LMTP client (hopefully! verify!) connects to the second one.