How FTP works.

FTP is based on a client-server configuration. Therefore, it allows you to transmit information regardless of the operating system you use. Even the system used by the hosting provider (Windows, Linux, MAC, etc.) is not relevant. To be able to use it, it is necessary to have a server and also a client. Check our tutorials to learn more about each type.

The communication is initiated when a connection is made from the client to the server. In addition, this connection is negotiated through the network port 21, also called control port. However, this will not be the port through which the information will be sent or downloaded. Indeed, this depends on the FTP mode selected.

FTP modes

Active mode: the server opens the initial connection. Consequently, it opens the connection on its port 20 and connects to the client on a random port greater than 1024. Moreover, this port is specified by the FTP client itself. Note that this is the least recommended option. Indeed, its use implies having a fairly wide range of ports open on your computer. It certainly carries many security risks.

Passive mode: the client opens the initial connection. In addition, it is the server that indicates which port to open. It will always be done on a network port greater than 1024 of the servers. Therefore, it is not necessary to have open ports on the computer. This is logical, since it will be the server that will open the connection.

We have already mentioned that the FT protocol was created several years ago. Even before hackers existed. Therefore, it was not recognized as a secure protocol. In fact, the information that travels between computer and server is in plain text. That is, without any kind of encryption.

What does the lack of encryption imply?

Well, this implies a considerable risk that the data will be captured. Indeed, an attacker could see our connection data and even view the information we are uploading. Even worse, they could download it using a Sniffer type software. These tools are capable of scanning the network for vulnerabilities.

Suppose you make a connection using plain FTP. As a result, you will see a warning that the connection is not secure. We have established that the FTP connection is not secure at all. Because of this, two secure versions were subsequently born: FTPS and SFTP. Although they are almost the same acronym, they are not at all the same. Let’s take a look at what each one consists of.

Secure versions of FTP: FTPS and SFTP

What is FTPS?

FTPS works in the same way as conventional FTP. However, the main difference is that it has an SSL/TLS encryption layer underneath. Also, this layer is provided by a security certificate. It is known as Secure FTP and there are two types of connection:

• Explicit FTPS: This is the month used. In addition, we also recommend its use. A normal, unencrypted connection is made. However, before sending any sensitive data, TLS negotiation is required to encrypt the connection.
• Implicit FTPS: It is in disuse. In fact, it is not available on most servers. The negotiation of the secure connection is done before any FTP command is sent.

What is SFTP?

SFTP is a wholly different protocol from conventional FTP. Indeed, it is based on the SSH (Secure Shell) protocol. In addition, the entire connection is encrypted and made through network port 22. They differ not only in encryption. Additionally, it is a protocol with more functionalities than conventional FTP. For example, we have the execution of CLI (Command Line Interface) commands.

SFTP stands for Secure File Transfer Protocol. Through it, we can exchange encrypted data between the client and the server. It uses Secure Shell (SSH) for this purpose. In addition, we can not only transfer files via SFTP. Indeed, we can view directories, rename them or limit rights. An SFTP program allows you to upload files for your website to your webspace. We can even create a backup of the website with SFTP. With a SFTP program, you can also delete entire files and folders. Indeed, if you delete contents, they will no longer appear to visitors of your website. In short, SFTP is the successor to FTP. The major difference is greater security. This is indicated by the addition Secure.

Conclusion

Security is a fundamental concern in any technology environment. Certainly, in the world of hosting, it is an element that also depends on the provider. However, it is primarily an element to be taken care of by the user. Today we talked about the differences between FTP and SFTP. Logically, you may have noticed that the main difference is related to security. Therefore, it is not currently recommended using a conventional FTP connection to connect. There are certainly exceptions. For example, we can use them for specific cases for reasons of urgency. Mostly when we need a fast connection and do not have much time to configure it. Moreover, when the data to be shared is not sensitive.

Consequently, when you connect via FTP to upload or download data, remember to always do it via FTPS or SFTP. This way, we are taking care of our data. Please keep in mind that hackers are always on the prowl. Therefore, it is our duty to make things more difficult for them. See you soon!

The post What is the difference between FTP and SFTP? appeared first on Linux Windows and android Tutorials.

What is vnStat?

The best definition of Vnstat can be found on the project’s own website:

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as an information source. This means that vnStat won’t actually be sniffing any traffic and also ensures light use of system resources regardless of network traffic rate.

Therefore this tool is quite well known within the community and among sysadmins. It is quite simple to use and as you will see below it is easy to install.

Install vnStat on Debian 11 / 10

One of the fastest and most immediate ways to install vnStat on Debian 11 / 10 is to install it from the official repositories.

Although this is not the only way to get the program, it is the easiest method for newbies.

So, open a terminal or from an SSH session, install the security patches in the distribution:

sudo apt update
sudo apt upgrade

Next, you can install the vnStat package as follows:

sudo apt install vnstat

After it is installed, start the application service.

sudo systemctl start vnstat

This will complete the installation and you will be able to use it.

Install the latest version of vnStat on Debian 11 / 10

The previous method has a big problem and it is that the version that appears in the official repositories of Debian 11 / 10, is very outdated. So it is advisable to always install the latest version following these steps that I will describe.

First, install the packages needed to do the compilation, as well as some dependencies:

sudo apt install build-essential gcc make libsqlite3-dev

Then download the latest stable version, which at the time of writing this post, is 2.8.

wget https://humdi.net/vnstat/vnstat-2.8.tar.gz

Decompress the downloaded file

tar -xvzf vnstat-2.8.tar.gz

As a result of executing the above command, a folder called vnstat-2.8 will be generated which you will need to access and from there configure the package for compilation:

cd vnstat-2.8
./configure --prefix=/usr --sysconfdir=/etc

Now, compile the package and install it with this pair of commands:

sudo make
sudo make install

If everything went well, you will be able to run the vnstat command and display, for example, the installed version:

vnstat -v

Output:

vnStat 2.8 by Teemu Toivola <tst at iki dot fi>

Using the vnStat command

Before using the tool it is necessary to start the vnStat service. As we have installed it manually, there is no service installed so we have to create it.

Fortunately, to create it we will use the example file that comes with the code we have just compiled.

sudo cp -v examples/systemd/vnstat.service /etc/systemd/system/

Refresh the list of services

sudo systemctl daemon-reload

And now yes, enable it so it can start with the system and start the service

sudo systemctl enable vnstat
sudo systemctl start vnstat

And check the status of the service

sudo systemctl status vnstat
● vnstat.service - vnStat network traffic monitor
     Loaded: loaded (/etc/systemd/system/vnstat.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2021-10-02 18:24:27 CEST; 11s ago
       Docs: man:vnstatd(8)
             man:vnstat(1)
             man:vnstat.conf(5)
   Main PID: 5939 (vnstatd)
      Tasks: 1 (limit: 2276)
     Memory: 612.0K
        CPU: 20ms
     CGroup: /system.slice/vnstat.service
             └─5939 /usr/sbin/vnstatd -n

Oct 02 18:24:27 osradar systemd[1]: Started vnStat network traffic monitor.
Oct 02 18:24:27 osradar vnstatd[5939]: Info: vnStat daemon 2.8 started. (pid:5939 uid:0 gid:0 64-bit)
Oct 02 18:24:27 osradar vnstatd[5939]: Info: Monitoring (1): eth0 (1000 Mbit)

After waiting a few minutes, you can start using it.

vnstat

By default, it takes the active interface, but you can change it:

vnstat -i [interface]

When an interface is monitored, a new database with logs is created. You can delete it and reset the statistics.

sudo vnstat -i [interface] --remove --force

In this case, you have to specify the interface to monitor.

Enjoy it.

Conclusion

So now you know how to install and use vnStat on Debian 11 / 10 This command although simple allows you to find answers to the operation of a network interface and to know if the behavior is as expected…

The post Install and use vnStat on Debian 11 / 10 appeared first on Linux Windows and android Tutorials.

MariaDB is a well-known archi Database Relationships Management System that is a MySQL fork. This is due to the purchase of Sun Mycrosystem by Oracle. It is perfectly compatible with MySQL and is available in most Linux distributions.

In Rocky Linux 8 / AlmaLinux 8 / CentOS 8 the version of MariaDB that is available in the official repositories is 10.3 but recently has seen the release of version 10.6 with some interesting new features.

So, if you want to take advantage of having a recent version of this database manager, then welcome.

Install MariaDB 10.6 on Rocky Linux 8 / AlmaLinux 8 / CentOS 8

MariaDB’s support with Linux is quite good and proof of this is that it provides us with a dedicated repository for Rocky Linux 8 / AlmaLinux 8 / CentOS 8 to facilitate installation.

So, access your server or start a terminal session and update the system. In this post, I worked as the root user. Also, you can use sudo if your user has permission to do so.

dnf update

And make sure you have installed the nano text editor

dnf install nano

Then we have to create a new repository entry in the DNF configuration which is /etc/yum.repos.d/

So, create a file called mariadb.repo

nano /etc/yum.repos.d/mariadb.repo

And add the following information:

[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.6/rhel8-amd64
module_hotfixes=1
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1 

Then save the changes and close the editor.

Now install MariaDB 10.6

dnf install mariadb-server

During the installation, you will have to accept the GPG key from the repository and the installation will continue.

Then you have to start the MariaDB service:

systemctl start mariadb

and proceed to the configuration with the mariadb_secure_installation script

mariadb_secure_installation
Switch to unix_socket authentication [Y/n] y
Remove anonymous users? [Y/n]
Disallow root login remotely? [Y/n]
Remove test database and access to it? [Y/n]
Reload privilege tables now? [Y/n]

After the installation is complete, check the installed version:

mysql --version
mysql  Ver 15.1 Distrib 10.6.3-MariaDB, for Linux (x86_64) using readline 5.1

So, you can enjoy MariaDB.

Conclusion

MariaDB 10.6 is a good improvement over previous versions. But it is not always available in the official repositories of other Linux distributions. Today you have learned how to install it in Rocky Linux 8 / AlmaLinux 8 / CentOS 8.

The post How to install MariaDB 10.6 on Rocky Linux 8 / AlmaLinux 8 / CentOS 8? appeared first on Linux Windows and android Tutorials.

CentOS is one of the most solid and stable distribution that there is, but this has a price to dispose of old packages. And one of them is the Linux kernel.

Currently, if you want to install Rocky Linux 8 / AlmaLinux 8 / CentOS 8, you will have to install version 4.18 and this is a problem for recent hardware. One case of this is AMD’s Ryzen processors that with each new version of the kernel have seen an improvement in performance and support. So, if you install Rocky Linux 8 / AlmaLinux 8 / CentOS 8 and your hardware is recent, it’s a good idea to do a kernel upgrade.

In this sense, the 5.13 kernel is supported by the Rocky Linux 8 / AlmaLinux 8 / CentOS 8 community. This guarantees an easy and safe installation. Also, this kernel is frequently patched by the community team bringing even more stability.

So, let’s do it.

Install Kernel 5.13 on Rocky Linux 8 / AlmaLinux 8 /CentOS 8

Many people like to have the latest kernel installed so they can get the most out of the hardware they have. That’s why it’s in their best interest to know how to do it.

So, open a terminal and upgrade your distribution

sudo dnf update

You can execute these commands as the root user or with a sudo user.

Thanks to an external repository called elrepo we can have different versions of the kernel. For example, in this repository, we can install the latest available kernel or the LTS version of it. That is, the repository is very well maintained.

So, to add it to the system, just run the following command:

sudo dnf install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm

It then adds the GPG key from the repository in order to ensure that the packages are adequate and to indicate to the system that it is reliable.

sudo rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

And now yes, install the 5.13 kernel by running the following command.

We will also install some packages needed to develop with the kernel such as headers and devel.

sudo dnf --enablerepo=elrepo-kernel install kernel-ml kernel-ml-devel kernel-ml-headers

At the end of the installation, restart the system

When you start again, check the changes:

uname -r
5.13.7-1.el8.elrepo.x86_64

So, you already have the 5.13 kernel on CentOS 8.

Conclusion

The Linux kernel is an essential part of our system. Therefore, it is advisable to be careful when installing it. In addition, it is only recommended to install it if you have hardware failures or if you have a very recent one.

The post How to install Linux Kernel 5.13 on Rocky Linux 8 / AlmaLinux 8 /CentOS 8? appeared first on Linux Windows and android Tutorials.

reveal.js is an open-source HTML presentation framework. It’s a tool that enables anyone with a web browser to create fully-featured and beautiful presentations for free.

Presentations made with reveal.js are built on open web technologies. That means anything you can do on the web, you can do in your presentation. Change styles with CSS, include an external web page using an <iframe> or add your own custom behavior using our JavaScript API.

So in these times of pandemic, this tool can be quite useful for many students and teachers.

Install Reveal.js on Ubuntu 20.04 / Debian 10

1.- Install required packages

Before starting the installation of Reveal.js it is necessary to install some packages first.

So, open a terminal, and run the following command

sudo apt install curl gnupg2 unzip git

Now we have to install NodeJS version 14. For this, we have to add the nodejs repository.

curl -sL https://deb.nodesource.com/setup_14.x | sudo bash -

This will start the whole process of adding the repository along with its GPG key.

Once the process is finished, you can install NodeJS

sudo apt install nodejs

You can check the installed version by running the following command:

node -v

Output:

v14.17.2

2.- Download and install Reveal.js on Ubuntu 20.04 / Debian 10

Now we can start the download and for that, we’ll clone the Reveal.js repository with Git.

git clone https://github.com/hakimel/reveal.js.git

Once the cloning is done, we will have a folder called revel.js access it and install the application.

cd reveal.js
sudo npm install

After you have installed all the dependencies of the application, you can run it using the following command.

npm start

And you will get a screen output similar to this one:

   reveal.js@4.1.3 start /home/angelo/reveal.js
   gulp serve 
 [22:31:04] Using gulpfile ~/reveal.js/gulpfile.js
 [22:31:04] Starting 'serve'…
 [22:31:04] Starting server…
 [22:31:04] Server started http://0.0.0.0:8000
 [22:31:04] LiveReload started on port 35729
 [22:31:04] Running server

This indicates that reveal is running through port 8000 which is the default port. You can also change this port by using the --port

npm start -- --port=8001

Optionally, you can create a new system service to manage reveal.

sudo nano /lib/systemd/system/reveal.service

And add the following.

[Service]
Type=simple
User=root
Restart=on-failure
WorkingDirectory=/home/angelo/reveal.js
ExecStart=npm start

Save the changes, close the editor. And refresh systemd. Please replace angelo with the current user

sudo systemctl daemon-reload

Now you can start, stop, and enable it as a system service.

Now, open your web browser and go to http://your-server:8000 and you will see the default reveal.js presentation which indicates that the installation has been a success.

So, enjoy it.

Conclusion

In this time of the pandemic, in many places education has become distant. Well, there are many tools to help with this. One of them is to reveal that it is presented to us as a great alternative to PowerPoint for the creation of presets.

So, now you know how to install it. You can now create fantastic presentations using web technologies.

The post How to install Reveal.js on Ubuntu 20.04 / Debian 10? appeared first on Linux Windows and android Tutorials.

According to the project website:

Ajenti is An admin’s tool for a more civilized age, providing you with a fast and secure way to manage a remote Linux box at any time using everyday tools like a web terminal, text editor, file manager and others.

The application is open source but has two licenses. An open one that we can use in personal projects but if you want to use it in production environments then it becomes paid.

In any case, we are talking about a solid, robust project that is always active. Thanks to being created with state-of-the-art technology such as Python, Angular.JS, or GEvent the application does not consume many resources. This makes it ideal for almost any environment.

Install Ajenti Control Panel on Ubuntu 20.04 / Debian 10

There are two ways to install Ajenti. One is through an automated script that makes the process bearable. The other is by hand which is a little more tedious but not too difficult either.

Method 1

First, open a terminal or start an SSH session and update the system

sudo apt update
sudo apt upgrade

And then execute this command to download and run the script

curl https://raw.githubusercontent.com/ajenti/ajenti/master/scripts/install.sh | sudo bash -s -

With this script, you can make an automatic installation of Ajenti and it is a very easy and safe method.

Method 2:

However, there is a manual installation method that can be used on other operating systems and gives more control over the process.

So, install the necessary dependencies:

sudo apt-get install build-essential python3-pip python3-dev python3-lxml libssl-dev python3-dbus python3-augeas python3-apt ntpdate

Then, update PIP.

sudo pip3 install setuptools pip wheel -U

And finally install Ajenti using the following command:

sudo pip3 install ajenti-panel ajenti.plugin.augeas ajenti.plugin.auth-users ajenti.plugin.core ajenti.plugin.dashboard ajenti.plugin.datetime ajenti.filemanager ajenti.plugin filesystem ajenti.plugin.network ajenti.plugin.notepad ajenti.plugin.packages ajenti.plugin.passwd ajenti.plugin.plugins ajenti.power ajenti.plugin.services ajenti.plugin.settings ajenti.plugin.terminal

You will receive a message like this at the end of the execution.

You can now manage Ajenti as a system service using systemctl

Then, you can open it with the following address https://your-server:8000 and you will see the Login screen.

Enter the credentials of any user of the system and finally, you will see the dashboard.

So, enjoy it.

Conclusion

Ajentni is an interesting project that provides us with a quite simple and powerful control panel. Thanks to Python and Javascript we have a modern application that will help us with our servers.

The post Install Ajenti Control Panel on Ubuntu 20.04 / Debian 10 appeared first on Linux Windows and android Tutorials.

In terms of proprietary database managers perhaps Oracle Database, IBM DB2, and Microsoft SQL Server are the most used and common options by many companies. They have the great advantage of having large companies behind them that provide a high level of support to their operations.

Also, there are other quite competent open-source options such as MySQL, PostgreSQL, or Percona. However, many companies still trust their data to proprietary options and the fact that we can install them in Ubuntu speaks well of our system. So let’s go for it.

Install Microsoft SQL Server on Ubuntu 20.04 / Debian 10

As you can imagine, SQL Server is not available in the official Ubuntu repositories but it is available through the repository offered by Microsoft.

So, open a terminal or connect via SSH and update the system:

sudo apt update
sudo apt upgrade
sudo apt install software-properties-common 

Then import the GPG key from the Microsoft repository.

sudo wget -qO- https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -

After that, add the SQL Server repository as such.

sudo add-apt-repository "$(wget -qO- https://packages.microsoft.com/config/ubuntu/18.04/mssql-server-2019.list)"

Next, refresh APT.

sudo apt update

And now you can install Microsoft SQL Server by executing the following command:

sudo apt install mssql-server
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  gawk gdb libbabeltrace1 libc++1 libc++1-10 libc++abi1-10 libdw1 libmpfr6 libpython2-stdlib libpython2.7-minimal libpython2.7-stdlib libsasl2-modules
  libsasl2-modules-gssapi-mit libsigsegv2 libsss-nss-idmap0 python-is-python2 python2 python2-minimal python2.7 python2.7-minimal
Suggested packages:
  gawk-doc gdb-doc clang libsasl2-modules-ldap libsasl2-modules-otp libsasl2-modules-sql python2-doc python-tk python2.7-doc binutils binfmt-support
Recommended packages:
  libc-dbg libcc1-0 gdbserver
The following NEW packages will be installed:
  gawk gdb libbabeltrace1 libc++1 libc++1-10 libc++abi1-10 libdw1 libmpfr6 libpython2-stdlib libpython2.7-minimal libpython2.7-stdlib libsasl2-modules
  libsasl2-modules-gssapi-mit libsigsegv2 libsss-nss-idmap0 mssql-server python-is-python2 python2 python2-minimal python2.7 python2.7-minimal
0 upgraded, 21 newly installed, 0 to remove and 29 not upgraded.
Need to get 235 MB of archives.
After this operation, 1,102 MB of additional disk space will be used.
Do you want to continue? [Y/n]

This way it will be installed.

Preparing Microsoft SQL Server for the first use

During the installation process, you will notice that at the end, you will get an output screen similar to this one:

Setting up python-is-python2 (2.7.17-4) ...
Setting up libc++1:amd64 (1:10.0-50~exp1) ...
Setting up mssql-server (15.0.4102.2-4) ...

+--------------------------------------------------------------+
Please run 'sudo /opt/mssql/bin/mssql-conf setup'
to complete the setup of Microsoft SQL Server
+--------------------------------------------------------------+

Processing triggers for man-db (2.9.1-1) ...
Processing triggers for mime-support (3.64ubuntu1) ...
Processing triggers for libc-bin (2.31-0ubuntu9.2) ...

In it, we are told that it is necessary to configure the application before using it and it even tells us the command to start the configuration.

sudo /opt/mssql/bin/mssql-conf setup
usermod: no changes
Choose an edition of SQL Server:
  1) Evaluation (free, no production use rights, 180-day limit)
  2) Developer (free, no production use rights)
  3) Express (free)
  4) Web (PAID)
  5) Standard (PAID)
  6) Enterprise (PAID) - CPU Core utilization restricted to 20 physical/40 hyperthreaded
  7) Enterprise Core (PAID) - CPU Core utilization up to Operating System Maximum
  8) I bought a license through a retail sales channel and have a product key to enter.

Details about editions can be found at
https://go.microsoft.com/fwlink/?LinkId=2109348&clcid=0x409

Use of PAID editions of this software requires separate licensing through a
Microsoft Volume Licensing program.
By choosing a PAID edition, you are verifying that you have the appropriate
number of licenses in place to install and run this software.

Enter your edition(1-8):

The main configuration we have to do is to enter the license. In this case, I have used the Developer which is free and we can use it for the post.

Also, you have to accept the license terms and create the administrator key which has to be complex.

With this SQL Server will be installed but we are missing one more detail.

For now, you can check the status of the service to see if everything is in order:

sudo systemctl status mssql-server
● mssql-server.service - Microsoft SQL Server Database Engine
     Loaded: loaded (/lib/systemd/system/mssql-server.service; enabled; vendor preset: enabled)
     Active: active (running) since Thu 2021-03-25 20:39:29 CET; 3min 59s ago
       Docs: https://docs.microsoft.com/en-us/sql/linux
   Main PID: 3175 (sqlservr)
      Tasks: 136
     Memory: 587.6M
     CGroup: /system.slice/mssql-server.service
             ├─3175 /opt/mssql/bin/sqlservr
             └─3218 /opt/mssql/bin/sqlservr

Install SQL Server tools and UnixODBC

Although the Server is ready, we have to install other components like the Tools and fundamentally the UnixODBC connector without this we will not be able to make a connection with the server.

So, add the GPG key and the repository:

curl https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -
OK
wget https://packages.microsoft.com/config/ubuntu/19.10/prod.list
sudo mv prod.list /etc/apt/sources.list.d/mssql-release.list

After this, refresh APT to apply the change:

sudo apt update

And finally, install both the UnixODBC connector and the Mssql-tools

sudo ACCEPT_EULA=Y apt install mssql-tools unixodbc-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  autoconf automake autotools-dev libgdbm-compat4 libltdl-dev libodbc1 libperl5.30 m4 msodbcsql17 odbcinst odbcinst1debian2 perl perl-modules-5.30 unixodbc
Suggested packages:
  autoconf-archive gnu-standards autoconf-doc libtool gettext libtool-doc unixodbc-bin m4-doc perl-doc libterm-readline-gnu-perl | libterm-readline-perl-perl make
  libb-debug-perl liblocale-codes-perl
Recommended packages:
  libtool
The following NEW packages will be installed:
  autoconf automake autotools-dev libgdbm-compat4 libltdl-dev libodbc1 libperl5.30 m4 msodbcsql17 mssql-tools odbcinst odbcinst1debian2 perl perl-modules-5.30 unixodbc
  unixodbc-dev
0 upgraded, 16 newly installed, 0 to remove and 29 not upgraded.
Need to get 9,845 kB of archives.
After this operation, 53.9 MB of additional disk space will be used.
Do you want to continue? [Y/n]

After the installation, add the directory to the bash_profile so that the command is available from the whole system.

echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bash_profile

In the end, you can connect to the shell by running:

sqlcmd -S 127.0.0.1 -U SA

Note: if you cannot execute the command, log out and try again.

Now you will be able to use Microsoft SQL Server on Ubuntu 20.04 / Debian 10

Conclusion

Microsoft SQL Server is pretty good at what it does and that is why many companies have it as their database manager. Having it available on Ubuntu 20.04 / Debian 10 is not a difficult task and brings us even closer to the integration between Microsoft and Linux products.

The post How to install Microsoft SQL Server on Ubuntu 20.04 / Debian 10? appeared first on Linux Windows and android Tutorials.

As we all know Rocky Linux is one of the most anticipated distributions of this year. The so-called, with permission of AlmaLinux OS, the replacement for CentOS, is finally approaching us with a fully stable and production-ready version.

Ideally, if you are starting a new project, you will have to download the ISO image and install it from scratch, but if you have a production server, this may not be ideal. So the migration process although easy can always be problematic.

So, let’s get started.

Migrate from CentOS 8 to Rocky Linux 8.4

The process is quite simple thanks to a script that the community has prepared. So it shouldn’t take that long.

First, you have to completely upgrade your system. This step is essential for the success of the process.

sudo dnf upgrade

Then, reboot the system to make sure all changes are applied including kernel-related changes.

sudo reboot

After the system reboots, we can now download the script.

curl -O https://raw.githubusercontent.com/rocky-linux/rocky-tools/main/migrate2rocky/migrate2rocky.sh
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 27069  100 27069    0     0   128k      0 --:--:-- --:--:-- --:--:--  128k

Now give the script permissions to run

chmod +x migrate2rocky.sh

Now, we can run it locally with the command

sudo bash migrate2rocky.sh -r

This will start the whole migration process which may take some time depending on your computer resources and connection speed.

At the end, you will see a message like the following

And finish the process by rebooting the system

sudo systemctl reboot

When it starts, you can verify the migration by running

cat /etc/os-release

So, enjoy it.

The post How to migrate from CentOS 8 to Rocky Linux 8.4 appeared first on Linux Windows and android Tutorials.

PostgreSQL 13 is the latest stable version of what is perhaps the most advanced open-source relational database manager. So many sysadmin need to have it on the different servers.

If you want to know all the news or at least the most important ones, you can read this post

PostgreSQL 13 is available

Well, PostgreSQL 13 comes with many important improvements and it’s a good time to install it. That’s what this post is about.

So let’s go for it.

Install PostgreSQL 13 on Debian

PostgreSQL is included in the official Debian repositories, but not in version 13 but in version 11.

The installation of PostgreSQL 13 is possible thanks to the repository it has for APT package managers that is used by Debian, Ubuntu, Linux Mint and derivatives.

So let’s start.

First, open a terminal session or connect to your server using SSH. Then, install some necessary packages:

:~$ sudo apt install gnupg gnupg2

At the end, the PostgreSQL 13 repository should be added to the list of Debian software sources. To do this, create the following file:

:~$ sudo nano /etc/apt/sources.list.d/pgdg.list

And in it he adds the following:

deb http://apt.postgresql.org/pub/repos/apt/ buster-pgdg main

Then save the changes by pressing CTRL + O and close the file by pressing CTRL + X.

For the repository to be accepted by the system, you need to add the gpg key to it. To do this, use the following command:

:~$ wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
OK

Once the process has been completed, simply update the APT cache.

:~$ sudo apt update

You can now view all the packages related to PostgreSQL 13 by typing

:~$ sudo apt install postgresql-13

But don’t press enter, just press the TAB key and you’ll see the following:

As you can see in the image, we have PostgreSQL 13 available. So to install it run the following command:

:~$ sudo apt install postgresql-13
Reading package lists... Done
Building dependency tree 
Reading state information... Done
The following additional packages will be installed:
libgdbm-compat4 libjson-perl libllvm7 libperl5.28 libpq5 libxslt1.1 perl pgdg-keyring postgresql-client-13 postgresql-client-common postgresql-common ssl-cert
Suggested packages:
perl-doc libterm-readline-gnu-perl | libterm-readline-perl-perl make libb-debug-perl liblocale-codes-perl postgresql-doc-13 openssl-blacklist
Recommended packages:
libjson-xs-perl sysstat
The following NEW packages will be installed:
libgdbm-compat4 libjson-perl libllvm7 libperl5.28 libpq5 libxslt1.1 perl pgdg-keyring postgresql-13 postgresql-client-13 postgresql-client-common postgresql-common
ssl-cert
0 upgraded, 13 newly installed, 0 to remove and 10 not upgraded.
Need to get 34.5 MB of archives.
After this operation, 145 MB of additional disk space will be used.
Do you want to continue? [Y/n]

Now we’ll see if everything went well.

Testing the installation

By default, Debian when installing PostgreSQL starts and enables the service. Therefore, it is ready to be tested. However, if you want to stop the service, you can use this command:

:~$ sudo systemctl stop postgresql

On the other hand, the best way to know if PostgreSQL is ready for work is to execute some command from the console. So we’ll access it first:

:~$ sudo -i -u postgres

Remember that the PostgreSQL console is accessed through the postgres user.

And finally, we access with this command:

:~# psql

Once inside, we can, for example, display all the databases in the system:

:~# \l

And so we can work without problems with PostgreSQL.

Conclusion

PostgreSQL 13 is a powerful database manager that is used in many projects worldwide. This makes many people want to have the latest stable versions to take even more advantage of the tool.

Please share this post and join our Telegram channel.

The post How to install PostgreSQL 13 on Debian 10? appeared first on Linux Windows and android Tutorials.

Shutting down and restarting a computer is a simple and routine task that is also important for the operating system. That is why we all do it.

Things can get complicated when we need to do it using the terminal because it is not a normal process. This may be needed when creating bash scripts or if some of our applications require it.

So for this, we have several commands and situations. Let’s go for it.

How to Shutdown Linux

To shutdown the computer immediately, you just have to run the following command

shutdown -h now

Note: this command has to be executed with root permissions or using the sudo command.

This way, the system will immediately start the shutdown process.

Another way to do this is with the poweroff command.

poweroff

Also, this command requires root privileges.

shutdown Linux after a specified time

Imagine you are downloading a file and you know approximately how much time is left. But you have to leave or do other things, you can “schedule” a system shutdown.

To do this, you can use the following syntax.

shutdown -h +[time]

For example, if you want the system to shut down in 20 minutes, just run:

shutdown -h +20

Also, you have to run the command with sudo or be root user.

Shutdown Linux at a specific time

On the other hand, if you know at what time you want to shut down the system, then you can also do it this way:

shutdown -h [time]

Replace [time] with the exact time in 24H format. For example, if we want the system to shut down at 20:30 hrs.

shutdown -h 20:30

Reboot Linux

The command to reboot the system is shutdown but adding the -r option

shutdown -r now

Or you can schedule it for a specific time:

shutdown -r 20:30

In the same way as with shutting down the system

Conclusion

It is always useful to know how to use the terminal and the utilities that we can take advantage of it. That’s why in this post, you learned how to do it hoping that it can always be useful to you.

More info: Shutdown page

The post How to Shutdown Linux using the terminal? appeared first on Linux Windows and android Tutorials.