Hotfix for courier-mta on Ubuntu 16.04

On Ubuntu 16.04 the installation of the Courier MTA package fails  with the following error message:

courier-mta.service is not a native service, redirecting to systemd-sysv-install
Executing /lib/systemd/systemd-sysv-install enable courier-mta
insserv: script courier-mta: service courier-mta already provided!
insserv: exiting now!

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Howto: Courier-MTA forward only setup

Folgendes Aufgabenstellung:

  • Es gibt ein zentrales Mail-Relay (“Relay”)
  • Es gibt einen Rechner mit einem lokalem Mailserver, bei dem smartd-Alarme etc. Cron-Jobs auf dem root-Account aufschlagen (“Server”)
  • Die Mails des Rechners sollen an einen Account auf dem Relay geschickt werden, damit sie (zusammem mit den Mails anderer Rechner) gelesen werden

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Ubuntu 15.10 fulldisk encryption howto

The following howto has been partly stolen from somewhere else . I adapted it to my situation. The main setup is the same: The whole installation (swap + root fs + home) should reside in a single encrypted container so that at boot we only have to provide one password and hibernate is encrypted too. Only the bootloader is unencrpyted.

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Terminal screensharing with screen (howto)

on server / computer hosting the meeting:

add user remoteguest:

useradd -m remoteguest

set suid:

chmod u+s /usr/bin/screen

give read permission:

chmod a+r /var/run/screen

share terminal session:

screen -L -S Multiuser

Set multiuser permission (hit Ctrl-A to enter commands when in screen):

:multiuser on 
:acladd remoteguest

on client / participant

login to host / server:

ssh ...

$USERNAME is the user under which you started the first screen command:

screen -x $USERNAME/Multiuser
ssh remoteguest@
screen -x glutz/Multiuser