Ubuntu 20.04: add swap space

In this tutorial, I will walk you through how to add swap space on Ubuntu 20.04 and above. A swap space on Linux is a location on the disk, which allows the OS to load the random access memory (RAM), on Windows we find this type of file pagefile.sys By default, on server versions of …

Read more



Docker: manage your containers with Portainer.io

In this tutorial, I will explain how to manage your Docker containers with Portainer. Portainer is an application that runs under Docker and will allow you to have a graphical interface (Web) to manage your containers under Docker. With Portainer you will be able to: Create / Modify / Delete containers Administrators your containers (SSH …

Read more



ncdu: analyze disk space in command line on Linux

In this “‘little” tutorial, I will explain how to view and analyze the space in the command line on Linux with ncdu. If you are adapted from WinDirStat or TreeSize on Windows, the ncdu utility on Linux allows you to have the “same” thing in a terminal. The first thing to do is to install …

Read more



Ubuntu – Extend LVM partition and disk

In this tutorial, I will explain how to extend a disk’s partition and then the LVM disk. To understand what we are going to do in this tutorial, I have a virtual machine with Ubuntu Server 20.04 installed on an LVM disk, following the addition of data, I must increase the storage capacity, for that …

Read more



PFX certificate: extract the certificate and the private key

In this tutorial, I will explain how to extract the certificate and the private key from a certificate in PFX format with OpenSSL. The easiest way to use OpenSSL is to use a Linux computer. 1. Copy the PFX file to your computer where OpenSSL is installed. 2. The first step will be to extract …

Read more



Docker: installation and concrete use on Ubuntu

Introduction In this tutorial, I will explain to you how to install Docker on Ubuntu and then through a concrete example how and why to use Docker. At the time of writing this tutorial (in 2021) as SysAdmin, I was having a hard time finding a concrete use for containers including Docker (so I’ll let …

Read more



SSH: authentication by keys

In this tutorial, I will explain how to connect to a linux server / computer in SSH without password using a key pair (private / public). Generate the key pair with ssh-keygen To generate a pair of keys, you must have an SSH client available, it is possible to do it from Windows 10 or …

Read more



Ubuntu: create a user and add it to the sudo group

Small memo to create a user on Ubuntu and add it to the sudo group: Enter the password for the current user (sudo) if necessary, then enter the password for the new account twice and enter additional information as required. Confirm the information by pressing Enter. Now we add the user to the sudo group. …

Read more