Thanks for the pointers, my comments below.
# netstat -tulpn | grep ":10024"
when this error occurs is most likely revealing that amavis is running
on this port. But still knowing is knowing, guessing is guessing.
You're right, I will check that next time. However, as I usually
discover the issue hours later, I guess that whoever that is blocking
10024 will have terminated by then.
Actually systemd is running a generator to interpret /etc/init.d/* and
dynamically creates .service files, which are executed. The generator
is somewhere at /lib/systemd/system-generators/systemd-sysv-generator
and it's results should be at /run/systemd/generator.late/* .
D'oh, of course.
There is quite a lot going on in /run/systemd/generator.late/, here are
the amavis files
ls -l /run/systemd/generator.late/amavis*
/run/systemd/generator.late/amavisd-new.service -> amavis.service
amavis.service is the one launching /etc/init.d/amavisd-new, but the
amavisd-new.service -> amavis.service softlink is VERY suspicious.
This is confirmed by :
systemctl list-unit-files | grep amavis
So it would appear I have 2 amavis instances running, no wonder they
eventually fight over the port. (the same goes for the snmp agent...)
I'll try to disable one of them (time to fully understand how this
auto-generation is exactly done, and why this softlink is created...),
and report here, but probably in one month or two, given the rarity of
Btw. you have an interesting configuration, as I thought amavisd is
it's own spamd daemon (using perl API) and therefore process spamd
isn't needed at all.
Indeed, now that you mention it, I thought that the only service
launched should have been amavis (this is, after all, the only one
speaking to postfix), with spamassassin being called/launched as needed.
The original configuration was done on Debian 6, and migration might
have gone awry (I'm looking at you, systemd).
If aforementioned services cleanup does not work, I guess I'll redo my
configuration from scratch.
Thanks for the help !