Linux Kernel Teaching

This is a collection of lectures and labs Linux kernel topics. The lectures focus on theoretical and Linux kernel exploration.
https://linux-kernel-labs.github.io/refs/heads/master/index.html

Once in a while a new program really surprises me. Reminiscing a while
ago, I came up with a list of eye-opening Unix gems. Only a couple of
these programs are indispensable or much used. What singles them out is
their originality. I cannot imagine myself inventing any of them.

fail2ban is an intrusion prevention framework that reads server (Apache, SSH, etc.) and uses iptables profiles to block brute-force attempts:

Meld is a visual diff tool that makes it easier to compare and merge changes in files, directories, Git repos, and more.

The LoRaWAN protocol, which efficiently supports low-power wireless devices over wide area networks, has become standard in the world of the industrial internet of things (IoT). One of its benefits is its support for end-to-end encryption. However, researchers are warning that while LoRaWAN itself is perfectly secure, poor device security and user mistakes in configuration and implementation can still lead to hacks and widespread operational disruption.

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The ISS cupola

As we can see the default Linux disk encryption implementation has a significant impact on our cache latency in worst case scenarios, whereas the patched implementation is indistinguishable from not using encryption at all. In other words the improved encryption implementation does not have any impact at all on our cache response speed, so we basically get it for free! That’s a win!

Ever considered setting up and running your very own git server? It’s actually quite easy! In this post, I’ll outline the steps I took to set up my own so that you can give it a try yourself. But first, why might you even want to go through the trouble of setting up your own server?

After all, there are a wide array of excellent and free to use choices out there, such as GitHub, GitLab, and the up-and-coming sourcehut.

One reason is ownership: in today’s world of corporate surveillance, rampant privacy violations, and data breaches, there is something to be said of truly owning your own data. Both git and the web itself were designed and built on principles of decentralization and distribution. Standing up your own server is one way to tap into that heritage.

It’s also just plain fun, at least if you’re into that sort of thing. You get to build something useful and put your name on it. It’s something you control. You get to decide how it works, how it looks, who can access it, and what exists on it.

Setting up a git server is actually relatively straight-forward. Almost all of the heavy lifting is done by git itself, but I will also introduce a few supplementary tools to handle things like access control and HTTP access.

Pipes are cool! We saw how handy they are in a previous blog post. Let’s look at a typical way to use the pipe operator. We have some output, and we want to look at the first lines of the output. Let’s download The Brothers Karamazov by Fyodor Dostoevsky, a fairly long novel.

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SSH is a powerful tool which often grants a lot of access to anyone using it to log into a server. In this post, I’m going to talk about a few different ways that you can easily improve the security of your SSH model without needing to deploy a new application or make any huge changes to user experience.

The central region of our galaxy, the Milky Way, contains an exotic collection of objects, including a supermassive black hole weighing about 4 million times the mass of the Sun (called Sagittarius A*), clouds of gas at temperatures of millions of degrees, neutron stars and white dwarf stars tearing material from companion stars and beautiful tendrils of radio emission.

The region around Sagittarius A* is shown in this new composite image with Chandra data (green and blue) combined with radio data (red) from the MeerKAT telescope in South Africa, which will eventually become part of the Square Kilometer Array (SKA).

Zoom up to new altitudes by downloading these #TopGun
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meetings, hangouts and happy hours here: https://bit.ly/topgunzoom.

To your favorite Pixar locations…and beyond! Let the fun begin with these rootin’, tootin’ video call backgrounds!

Am Wochenende haben sich mehrere Menschen nicht an die Auflagen gehalten. Polizisten lösten Partys auf und schlossen Eisdielen. Die Grünen kritisieren: Es fehle ein klarer Handlungsrahmen für Polizei und Ordnungsämter.

It’s early yet, but we’ll see once the bodies are buried