Unveiling Whiteout Files: Do you know how file deletions are handled between layers of a Docker image?

Unveiling Whiteout Files: Do you know how file deletions are handled between layers of a Docker image?

 Posted on November 9, 2023  |  9 minutes  |  Pierre-Olivier Mercier  • Other languages: fr

Union file systems are a mechanism for merging two or more file systems, to present them unified, under a single mount point for the user. The main idea behind this mechanism is to be able to alter the contents of the first file system (e.g. the contents of a CD-ROM) by writing all changes (additions, deletions, modifications) to the second (which could be a disk partition, a USB stick, …). [Read More]
kernel  container  docker  linux 

Using Waveshare e-ink screens without Raspberry Pi

Using Waveshare e-ink screens without Raspberry Pi

 Posted on August 2, 2023  |  9 minutes  |  Pierre-Olivier Mercier  • Other languages: fr

When it comes to e-ink displays, Waveshare is a rare manufacturer that allows you to buy displays of any size. Advertised as ESP32, Arduino and Raspberry Pi compatible, they are in fact compatible with any development board exposing the SPI protocol. Since Raspberry Pi boards have become hard to find in recent months, we’ll take a look in this article at how to use another Linux-based board to run a Waveshare display. [Read More]
linux  e-paper  kernel  spi 

Gamification of a Linux system administration course

Gamification of a Linux system administration course

 Posted on June 7, 2023  |  17 minutes  |  Pierre-Olivier Mercier  • Other languages: fr

System administration isn’t something that’s obvious to everyone, and it’s a subject that, when it’s more to do with the basics of networking and Linux, can seem a lot more daunting than learning about the latest trendy technologies (Docker, Terraform, Kubernetes, etc.). Also, with the bombardment of information and easy access to computer content and tutorials often more interesting than “classic” lectures, students are less and less attentive, present or participating. [Read More]
teaching  kernel  network  certificates 

RTL8153B support for 4.9 kernel

 Posted on March 17, 2019  |  1 minutes  |  Pierre-Olivier Mercier

If you buy a recent USB to Ethernet adapter, embedding a Realtek chip, you possibly face, like me, the following error, when connecting it:

r8152 4-1.1:1.0 (unnamed net_device) (uninitialized): Unknown version 0x6010
r8152 4-1.1:1.0 (unnamed net_device) (uninitialized): Unknown Device
[Read More]
kernel 

Support for the user namespace in grsecurity kernel

 Posted on October 31, 2018  |  1 minutes  |  Pierre-Olivier Mercier

Grsecurity has completely disabled, on purpose, the user namespace code for the kernel.

As the goal of this namespace is to gain (virtualy) root privilegies inside a namespace (in theory, it shouldn’t give more priviledgies than the one you initialy have outside of your namespace), there are some interesting use cases, or, in my case I need to perform some demo in front of my students.

[Read More]
kernel 

Linux Kernel Configurations

 Posted on April 20, 2015  |  1 minutes  |  Pierre-Olivier Mercier

My favorite distribution is Gentoo, for 7 years now. It allows me to have all the flexibility I need (the perfect world between stability with only legacy packages or recent ones on a constantly broken system; as in Gentoo, you always have choice) and it teaches me so many things each day.

As I’m used to control everything, here is a list of kernels' configurations I use currently.

[Read More]
kernel