Linux

Monitoring network traffic or bandwitdh usage is a must in a SysAdmin tasks. There are many differents tools to manage this monitoring, but one of my favorites is vnStat. The main advantage of this tool is the simplicity of its usage. Installation With Ubuntu, the way to install this tool is with apt. sudo apt install vnstat First steps Once installed, it is important to know which interfaces are going to be monitoried. For this, you can use next command ...

First step is to check the status of the interfaces. For this, we will use the net-tools package. sudo apt install net-tools Then, we can see the interfaces status ifconfig -a In my case, I have this status of my interface wlan0: ubuntu@ubuntu:~$ ifconfig -a wlan0 wlan0: flags=4098<BROADCAST,MULTICAST> mtu 1500 ether dc:a6:32:6c:xx:xx txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ...

In order to create a new user in a Linux Ubuntu distribution from terminal, you have to use this command. sudo adduser username After this, the system will ask you some parameters included the password. [23:43:24] ubuntu|zoar:~$ sudo adduser yvoictra Adding user `yvoictra' ... Adding new group`yvoictra' (1001) … Adding new user `yvoictra' (1001) with group`yvoictra' … Creating home directory `/home/yvoictra' ... Copying files from`/etc/skel' … New password: Retype new password: passwd: password updated successfully Changing the user information for yvoictra Enter the new value, or press ENTER for the default Full Name []: Yvoictra Room Number []: Work Phone []: Home Phone []: Other []: Is the information correct? [Y/n] y [23:46:40] ubuntu|zoar:~$ ...

There are lot of people that simply like to customize the appearence of the terminal, is my case. When you use a terminal during a lot of time, it usually helps to have a prompt more visible than the default one. Backup First of all, you should make a backup of the configuration file in order to fall back in case it is necessary. The file is at the user $HOME, so first step is to go the directory. ...

This blog have several items related to Raspberry. I decided to created this page to have all Raspberry Pi related posts, ordered. Info How to know which Raspberry do you have How to install Ubuntu in your Raspberry Pi 4 without Keyboard nor screen How to install Debian on a Raspberry Pi How to change the hostname in Ubuntu How to change language and timezone in Ubuntu Customization Customize the terminal with screenFetch How to add alias to your Linux Customize bash prompt with colours in Ubuntu Networking How to set up Wi-Fi on Ubuntu running on the Raspberry Pi 4 How to set up Wi-Fi on Debian running on the Raspberry Pi 4 How to resolve LAN hostnames with Ubuntu Monitoring How to Monitor an Ubuntu Server with Grafana and Prometheus How to monitor network traffic with vnStat Mail Configure Postfix to send e-mail using Sendinblue as SMTP server Security Protect your server with Fail2ban Integrate AbuseIPDB with Fail2ban Users How to create a new user in Ubuntu from terminal How to activate SUDO for a user in Ubuntu

To install Ubuntu in your Raspberry Pi 4 what you need is: Raspberry Pi 4 USB-C cable Mini SD Card (recommended 16 Gb or more) PC Mini SD Card reader in your PC RJ45 Ethernet cable Switch or Router of your network The first step is to install Ubuntu software in your SD Card. For this, you shoud go to the Raspberry Pi Downloads page, and download the Raspberry Pi Imager. ...

When we first install a new Operating System one of the typical request of the installation process is to set the hostname. To change the hostname in Ubuntu Linux system, you can follow different procedures. Editing system configuration files Edit the file /etc/hostname using the vi editor. Modify the old name and set the new one. $ sudo vi /etc/hostname Edit the file /etc/hosts and replace any ocurrence of the old name with the new one. ...

In some situations we need to know which packages we have installed in a Debian or Ubuntu system. In that case, we can use the tool dpkg, which will give us the information we need. dpkg Next command will give us the current packages installed with different states: dpkg --get-selections The states we can have are: install: The package is selected for installation. hold: A package marked to be on hold is not handled by dpkg, unless forced to do that with option –force-hold. deinstall: The package is selected for deinstallation (i.e. we want to remove all files, except configuration files). purge: The package is selected to be purged (i.e. we want to remove everything from system directories, even configuration files). If we want to filter packages, we can combine dpkg tool with grep tool. Here an example to filter the packages related with nginx: ...