severe fork() problems with new dovecot server

[J. Niklas]

On 01.03.2016 18:21, Dolf Schimmel wrote:

> Recently I played around a little with cgroups where you can limit the max number of processes per cgroup.
> Could it be that, perhaps, you've stumbled upon such a limit?
> Systemd does contain all services by default  in their own cgroup afaik,
> so it could be that you're using it unknowingly.

Yes, yes, \o/ ;-)

#> systemctl status dovecot.service
* dovecot.service - Dovecot IMAP/POP3 email server
   Loaded: loaded (/lib/systemd/system/dovecot.service; enabled; vendor
preset: enabled)
  Drop-In: /etc/systemd/system/dovecot.service.d
           `-ulimits.conf
   Active: active (running) since Tue 2016-03-01 15:28:29; 4h 24min ago
 Main PID: 10098 (dovecot)
    Tasks: 204 (limit: 512)
   CGroup: /system.slice/dovecot.service

There ist my "512". The way of systemd, ignoring all the config stuff
that has been there for decades while inposing its own, complex and very
sparsely documented ruleset on top is beginning to seriously annoy me.
At least I would have expected some sort of syslog message.

Just for the records, this can be changed by adding e.g.
TasksMax=4096
to the /etc/systemd/system/dovecot.service.d/ulimits.conf I cited
in my OP.

Now I'll have to wait and see how things will evolve tomorrow.
Thank you so much for the great hint!

-- 
kind regards,
              Jon