Tag Archives: Linux

Kubernetes: Pod resources.requests, resources.limits, and Linux cgroups

20 July 2025

How exactly do resources.requests and resources.limits in a Kubernetes manifest works “under the hood”, and how exactly will Linux allocate and limit resources for containers? So, in Kubernetes for Pods, we can set two main parameters for CPU and Memory – the spec.containers.resources.requests and spec.containers.resources.limits fields: resources.requests: affects how and where a Pod will be… Read More »

TCP/IP: OSI and TCP/IP models, TCP packets, Linux sockets and ports

19 July 2025

It’s difficult to describe in one post what thousands of books have been written about in a thousand pages, but today we’ll try to quickly review the basics of how hosts communicate on a network. First, let’s talk about the OSI and TCP/IP models, then about packet structure and connection establishment, and finally, we’ll… Read More »

Arch Linux: linux-firmware-nvidia: /usr/lib/firmware/nvidia/ exists in filesystem

9 July 2025

Even though the changes were announced in emails from Arch Linux, for some reason, many people have had problems with the latest update: in the Arch Linux subreddits on Reddit, people are complaining like “Everything is broken, what should I do now?” Let’s see how to complete the upgrade and what exactly has changed.… Read More »

Arch Linux: install in 2025 – partitions, encryption, and manual system installation

5 July 2025

Every time I start installing Arch Linux, it’s like a new journey: it seems like nothing much has changed over the years, but every time something new happens. I’ve written about this a lot, and it’s time to write about it again because I bought a new laptop. At first, I was too lazy to… Read More »

Arch Linux: mount LVM partitions and run mkinitcpio

15 April 2025

It’s not often, but sometimes I need to boot the system from a USB and rebuild initramfs-linux.img. This post is more of a quick note to myself on how, what, and where to mount on my laptop to run mkinitcpio, as I have LVM partitions, separate disk partitions for /boot, and swap. iwctl and WiFi… Read More »

Kubernetes: containers, and the “lost” SIGTERM signals

23 June 2024

We have an API service with Gunicorn in Kubernetes that periodically returns 502, 503, 504 errors. I started debugging it, and found a weird thing: there were no messages in the logs about the received SIGTERM, so I first went to deal with Kubernetes – why doesn’t it send it? The Issue So, here’s… Read More »

Arch Linux: failed to mount on real root

25 July 2023

I updated my Arch Linux yesterday, and for the first time in 9 years of using this system, I encountered an error when after a reboot the system could not mount a disk: ERROR: device UUID not found. mount: /new_root: can’t find UUID. ERROR: Failed to mount UUID on real root. You are now being… Read More »

Linux: saving laptop’s battery energy

19 November 2022

This time it became interesting to me – is it possible to somehow save the charge of the laptop battery? Not to say that it discharges quickly, it is enough for 5-6 hours of work, but it will not be too much, especially with the current power outages in Ukraine. Found several utilities, and… Read More »

Linux: create Gif or record video from the screen

29 September 2021

There are a lot of utilities to create a Git animation for Linux, but I like the peek. Besides the Gif, also can create files in the MP4, WebM, APNG formats. On the Arch Linux can be installed from the AUR: [simterm] $ sudo pacman -S peek [/simterm] Run it: [simterm] $ peek [/simterm] The… Read More »

Windows: Windows Subsystem for Linux and Ubuntu Linux installation

14 March 2021

Windows Subsystem for Linux (WSL) is a Windows subsystem that helps to run various Linux distribution directly from the Windows OS. WSL version 2 which is the default version now uses the Hyper-V virtualization under the hood to install and run Linux and share files and devices between both systems. Windows Subsystem for Linux… Read More »

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