Bug#272902: exim4: exim hangs for about 15s on startup

[Andreas Metzler]

On Wed, Sep 22, 2004 at 06:33:13PM +0100, George B. wrote:
> Package: exim4
> Version: 4.34-6
> Severity: normal
> 
> Hello,
> 
> Sorry, the subject line is not very descriptive. On system startup 
> exim hangs for a long time (I assume because it tries to connect to the 
> net). Until it finishes doing whatever it is doing the whole startup 
> procedure hangs.
[...]

Quoting /usr/share/doc/exim4-base/README.Debian.gz

Q: exim takes a very long time to start, I think it is making a DNS
  lookup although my /etc/host holds all the necessary information.

A: exim will indeed try to lookup the primary hostname at startup, however
it will first search for an AAAA record (IPv6), therefore triggering a
DNS lookup even if there is an IPv4 address for the hostname listed in
/etc/hosts.

There are a couple of ways to fix this:

* use dc_minimaldns='true'. (Either edit
  /etc/exim4/update-exim4.conf.conf or use dpkg-reconfigure exim4-conf).

* Use the FQDN as hostname in /etc/hostname, i.e. "foo.example.com"
  instead of just "foo". (You have to execute "hostname -F /etc/hostname"
  to implement the change to /etc/hostname.)

* Add an IPv6 record for your hostname (listed in /etc/hostname)
  to /etc/hosts. You can check with "getent hosts your_hostname" whether
  this was successful.

* Disable IPv6 host lookups in exim by setting "dns_ipv4_lookup = *".

* Set "primary_hostname = your_hostname"

            cu andreas