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Introduction In some circunstances it’s not easy to know the commands which exist to compress or decompress files in Linux (and Unix) environments. In this posts, I have wrote all the commands I have used for this. File Types TAR files Pack: tar -cvf file.tar file1 file2 file3 Unpack: tar -xvf file.tar See content: tar -tf file.tar GZ files Compress: gzip -9 file Decompress: gzip -d file BZ2 files Compress: bzip2 file Decompress: bzip -d file....

Grafana is an open source metric analytics & visualization tool which can help us to monitor the system with a nice Dashboard. Installing Grafana Grafana is available in the APT packages repository, however it could not be the latest version, so we’ll use the official Grafana repository. First, it is needed to install the software needed before install Grafana. sudo apt install -y apt-transport-https sudo apt install -y software-properties-common wget Next step is to download the GPG Key, in order to install signed packages:...

Introduction Some time ago I tried to configure a SMTP server in a host in the cloud, but because of some restrictions, the emails from that server were bounced. The problem was that the hosting provider didn’t configure the PTR DNS entries (more about DNS PTR entries) for some kind of hostings. When this happens the best solution is to use a SMTP relay server, by this way that server is in charge of the final delivery of the emails....

First off, as a prerequisite it is needed to have a CLI access to the Debian OS. It can be done using a keyboard and a screen connected to the Raspberry Pi, or using a SSH connection. If you have followed the post of how to install Debian On a Raspberry Pi 4, you should be able to access with SSH using the Ethernet (RJ45) port. Also, you should have the SSID and the password of your Wi-Fi connection, and it should be enabled the DHCP protocol in your router....

I have several Raspberry Pi and in all of them I have used the Ubuntu distro. However I also wanted to use Debian as it is one of the most used Linux distros. Besides Ubuntu is based on Debian, so I guess I will feel confortable with it. Debian vs Ubuntu Debian is more stable than Ubuntu, indeed, it is one of the most stable Linux. The releases in Debian are not as frequent as in Ubuntu, and the software updates in Debian usually don’t have the latest versions....

Introduction Nowadays, the knowledge to install a mail server is an important task for any System Administrator. In our case, we are going to see how to deploy a mail server with Postfix on Ubuntu. About Postfix Postfix is a free and open-source MTA (Mail Transfer Agent) which routes and delivers electronic mail (e-mails). As an SMTP server, Postfix implements a first layer of defense against spambots and malware. Can be used to send and receive e-mail....

In my diary activities usually I have to check the connectivity between two hosts. In this article I will explain which is the method I use to do it. ...

iPerf is a tool designed to test the bandwidth between two hosts using the network. It is a really simple, powerful CLI which allows generating traffic / load TCP or UDP between 2 hosts. You could use to measure the maximum bandwidth of the network between a client and a server. It can be used to do stress tests of the Ethernet, Wi-Fi or of your ISP. iPerf2 vs iPerf3, what is the difference?...