Linux on Matus Stafura

Automatically Restart MariaDB on Crash in Ubuntu with systemd

Thu, 16 Jul 2026 07:59:24 +0200

Why do you need to autorestart DB?

Database can crash from any problems like when the system runs out of memory, full disk and so on. And the website will be down until you notice it and restart the database manually.

The bare minimum you can do is to set it to restart automatically in Linux with systemd.

Note that this will not start DB when it is manually stopped.

How to Automatically Update a Git Repo on Login in Linux

Tue, 16 Sep 2025 00:00:00 +0000

Why would you want to do this?

Yeah, yeah, it happens even to the best of us.

You start committing changes to your repo, and then you forget to push them.

Then you go to another machine, and you realize that your repo is outdated.

BRUH!

To prevent this, you can easily set up a systemd user service that runs a script to git pull your repo every time you log in.

Limiting resources with ulimit in Linux

Mon, 03 Feb 2025 00:00:00 +0000

What is ulimit

ulimit is a builtin shell command that allows us to restrict system resources, for example the number of processes, number of open files, maximum logins.

Display the limits

The see the current resource limits for the logged-in user, run:

ulimit -a

Example Output

-t: cpu time (seconds)              unlimited
-f: file size (blocks)              unlimited
-d: data seg size (kbytes)          unlimited
-s: stack size (kbytes)             8192
-c: core file size (blocks)         0
-m: resident set size (kbytes)      unlimited
-u: processes                       22678
-n: file descriptors                2048
-l: locked-in-memory size (kbytes)  735404
-v: address space (kbytes)          unlimited
-x: file locks                      unlimited
-i: pending signals                 22678
-q: bytes in POSIX msg queues       819200
-e: max nice                        0
-r: max rt priority                 0
-N 15:                              unlimited

Setting resource limits

If you want to limit the number of processes for a user

How to Install and Configure Redis on a Separate DigitalOcean Droplet for Magento

Thu, 23 Jan 2025 00:00:00 +0000

Install redis on separate droplet to offload Redis from the Magento monolith.

Create a Droplet for Redis

Let’s create a droplet for Redis in DigitalOcean (DO from now on).

I chose the following minimal parameters (you can scale later):

Basic Droplet
Premium AMD: 1GB RAM, 25GB NVMe SSD, 1000GB transfer.

IMPORTANT: Make sure the new droplet is within the same VPC and Region as your Magento server.

Redis installation

Once the droplet is successfully created, SSH into the droplet and install Redis:

My first homelab

Mon, 20 Jan 2025 00:00:00 +0000

Finally, I found the time to set up my first homelab. To get hands-on experience with advanced Linux topics, virtualization, and Kubernetes, I needed a dedicated server. The truth is, you don’t need anything fancy—an old laptop can work just fine. I opted for a mini version since I might need to carry it to different locations.

Specs

Let me introduce the HP EliteDesk 800 i5-6500T. It’s second-hand but in excellent condition.

How to download torrents with transmission and docker

Mon, 13 Jan 2025 00:00:00 +0000

Since I set up my new homelab, I wanted to separate processes that could run independently on another PC. One of those processes is downloading torrents, which previously required my PC to be running and consumed valuable space.

Requirements

docker installed

Installation

Create a file named docker-compose.yaml and add the following content:

---
services:
  transmission:
    image: lscr.io/linuxserver/transmission:latest
    container_name: transmission
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
    volumes:
      - ./config:/config
      - ./downloads:/downloads
      - ./watch:/watch
    ports:
      - 9091:9091
      - 51413:51413
      - 51413:51413/udp
    restart: unless-stopped

Running transmission

While in the folder containing the docker-compose.yaml file, start the container. The volumes will be automatically created.

How to install man pages on an ubuntu docker image

Thu, 19 Dec 2024 00:00:00 +0000

As I am preparing for a Linux exam, I need to practice various commands on a separate Docker image and refer to manuals while using it.

By default, Docker images are minimal, and the Ubuntu image does not include man pages.

For instance, when you try to access a manual page, you encounter the following message:

root@54354b49f7a9:/# man man
This system has been minimized by removing packages and content that are
not required on a system that users do not log into.

To restore this content, including manpages, you can run the 'unminimize'
command. You will still need to ensure the 'man-db' package is installed.

To address this, you can use the unminimize command in the Dockerfile to restore the missing components. Here’s how: