Don't understand german? Read or subscribe to my english-only feed.

Archive for the 'Computer' Category

Postfix failing with “no shared cipher”

Monday, September 25th, 2023

I’m one of the few folks left who run and maintain mail servers. Recently I had major troubles receiving mails from the mail servers used by a bank, and when asking my favourite search engine, I’m clearly

What to expect from Debian/bookworm #newinbookworm

Sunday, June 11th, 2023

Debian v12 with codename bookworm was released as new stable release on 10th of June 2023. Similar to what we had with #newinbullseye and previous releases, now it’s time for #newinbookworm! I was the driving force at several of my customers to be well prepared for bookworm. As usual with major upgrades, there are some […]

Vortrag: Debugging für Sysadmins @ GLT23

Sunday, April 16th, 2023

Auf den Grazer Linuxtagen 2023 (GLT23) war ich als Referent mit einem Vortrag zum Thema “Debugging für Sysadmins” vertreten. In meinem Vortrag gibt es einen Überblick, welche Tools und Strategien rund ums Debugging in der Toolbox von Sysadmins nicht fehlen dürfen. Es gibt den Vortrag dank des wunderbaren c3voc-Teams bereits als Videomitschnitt online. Meine Vortragsfolien […]

Automatically unlocking a LUKS encrypted root filesystem during boot

Wednesday, March 22nd, 2023

Update on 2023-03-23: thanks to Daniel Roschka for mentioning the Mandos and TPM approaches, which might be better alternatives, depending on your options and needs. Peter Palfrader furthermore pointed me towards clevis-initramfs and tang. A customer of mine runs dedicated servers inside a foreign data-center, remote hands only. In such an environment you might need […]

RIP, Sven Guckes

Saturday, February 26th, 2022

Die älteste mir zugängliche Mail von Sven Guckes direkt an mich stammt aus dem Jahr 2002, und startet seinerseits mit: eine dokumentierte loesung – das ist prima! :-) Natürlich ging es um: Vim. Viele Mails unter anderem zum Kunsthaus Graz, den Chemnitzer Linux-Tagen, den Grazer Linuxtagen (GLT) und seinem Geek Brunch sollten folgen. Unvergessen bleibt […]

Debian bullseye: changes in util-linux #newinbullseye

Monday, July 5th, 2021

Continuing with #newinbullseye. One package that isn’t new but its tools are used by many of us is util-linux, providing many essential system utilities. There is util-linux v2.33.1 in Debian/buster and util-linux v2.36.1 in Debian/bullseye, and as usual there are many new features and options available. I don’t want to replicate the release notes provided […]

efivars is gone with Debian/bullseye #newinbullseye

Wednesday, June 9th, 2021

Continuing with #newinbullseye, it’s worth being aware of, that efivars is gone with the kernel version shipped as of Debian/bullseye. Quoting from wiki.debian.org/UEFI: The Linux kernel gives access to the UEFI configuration variables via a set of files under /sys, using two different interfaces. The older interface was showing files under /sys/firmware/efi/vars, and this is […]

What to expect from Debian/bullseye #newinbullseye

Thursday, May 27th, 2021

Debian v11 with codename bullseye is supposed to be released as new stable release soon-ish (let’s hope for June, 2021! :)). Similar to what we had with #newinbuster and previous releases, now it’s time for #newinbullseye! I was the driving force at several of my customers to be well prepared for bullseye before its freeze, […]

A Ceph war story

Friday, April 9th, 2021

It all started with the big bang! We nearly lost 33 of 36 disks on a Proxmox/Ceph Cluster; this is the story of how we recovered them. At the end of 2020, we eventually had a long outstanding maintenance window for taking care of system upgrades at a customer. During this maintenance window, which involved […]

How to properly use 3rd party Debian repository signing keys with apt

Tuesday, February 16th, 2021

(Blogging this, since this is a recurring anti-pattern I noticed at several customers and often comes up during deployments of 3rd party repositories.) Update on 2021-02-19: clarified, that Signed-By requires apt >= 1.1, thanks Vincent Bernat Many upstream projects provide Debian repository instructions like this: curl -fsSL https://example.com/stable/debian.gpg | sudo apt-key add – Do not […]

Grml 2020.06 – Codename Ausgehfuahangl

Friday, July 3rd, 2020

We did it again™, at the end of June we released Grml 2020.06, codename Ausgehfuahangl. This Grml release (a Linux live system for system administrators) is based on Debian/testing (AKA bullseye) and provides current software packages as of June, incorporates up to date hardware support and fixes known issues from previous Grml releases. I am […]

Some useful bits about Linux hardware support and patched Kernel packages

Wednesday, July 31st, 2019

Disclaimer: I started writing this blog post in May 2018, when Debian/stretch was the current stable release of Debian, but published this article in August 2019, so please keep the version information (Debian releases + kernels not being up2date) in mind. The kernel version of Debian/stretch (4.9.0) didn’t support the RAID controller as present in […]

Vortrag: Best Practices in der IT-Administration, Version 2019 @ GLT19

Monday, July 29th, 2019

Es ist schon ein Weilchen her, aber nachdem mich noch immer Leute darauf ansprechen: Auf den Grazer Linuxtagen 2019 (GLT19) war ich als Referent mit einem Vortrag zum Thema “Best Practices in der IT-Administration, Version 2019” vertreten. In dem 25-minütigen Vortrag geht es um die moderne IT-Administration und welche Best Practices es im Jahr 2019 […]

Debian buster: changes in coreutils #newinbuster

Friday, July 26th, 2019

Debian buster is there, and similar to what we had with #newinwheezy, #newinjessie and #newinstretch it’s time for #newinbuster! One package that isn’t new but its tools are used by many of us is coreutils, providing many essential system utilities. We have coreutils v8.26-3 in Debian/stretch and coreutils v8.30-3 in Debian/buster. Compared to the changes […]

Debian buster: changes in util-linux #newinbuster

Friday, July 26th, 2019

Debian buster is there, and similar to what we had with #newinwheezy, #newinjessie and #newinstretch it’s time for #newinbuster! Update on 2019-07-26 22:55 UTC: Cyril Brulebois pointed out, that findmnt (find a filesystem) was available in Debian/stretch already as part of the mount package, updated the blog post accordingly One package that isn’t new but […]

Inception: VM inside Docker inside KVM – Testing Debian VM installation builds on Travis CI

Wednesday, July 25th, 2018

Back in 2006 I started to write a tool called grml-debootstrap. grml-debootstrap is a wrapper around debootstrap for installing Debian systems. Using grml-debootstrap, it’s possible to install Debian systems from the command line, without having to boot a Debian installer ISO. This is very handy when you’re running a live system (like Grml or Tails) […]

Vortrag: Best Practices in der IT-Administration, Version 2018 @ GLT18

Tuesday, May 8th, 2018

Auf den Grazer Linuxtagen 2018 (GLT18) war ich als Referent mit einem Vortrag zum Thema “Best Practices in der IT-Administration, Version 2018” vertreten. In dem 25-minütigen Vortrag geht es um die moderne IT-Administration und welche Best Practices es im Jahr 2018 gibt. Es gibt den Vortrag als Videomitschnitt auf YouTube sowie in verschiedenen Formaten auch […]

Event: Infracoders-Graz – Best Practices in der IT-Administration

Saturday, March 17th, 2018

Am Dienstag (20.03.2018) findet das nächste Treffen der Infracoders-Graz statt. Ich wurde eingeladen einen Vortrag zu halten und werde zum Thema “Best Practices in der IT-Administration” referieren. Was: Vortrag zu “Best Practices in der IT-Administration” Wann: Dienstag, 20.03.2018 um 19:00 Uhr Wo: Aula X Space, Georgigasse 85, Graz Eintritt frei

Usage of Ansible for Continuous Configuration Management

Saturday, December 16th, 2017

It all started with a tweet of mine: I received quite some feedback since then and I’d like to iterate on this. I’m a puppet user since ~2008 and since ~2015 also ansible is part of my sysadmin toolbox. Recently certain ansible setups I’m involved in grew faster than I’d like to see, both in […]

Grml 2017.05 – Codename Freedatensuppe

Wednesday, June 14th, 2017

The Debian stretch release is going to happen soon (on 2017-06-17) and since our latest Grml release is based on a very recent version of Debian stretch I’m taking this as opportunity to announce it also here. So by the end of May we released a new stable release of Grml (the Debian based live […]