Category Archives: Linux OS

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Courtesy of nixpal.com

When you want to check if you have a 32-bit or a 64-bit Linux you can open a Terminal and just type:

file /sbin/init

arch

If you prefer to know how much about the RAM you installed on the PC, type:

free -m

grep MemTotal /proc/meminfo

for more detailed info you can try:

cat /proc/meminfo

grep MemTotal /proc/meminfo

if you prefer to monitor your RAM in real time.

Courtesy of validwebs.com

Configure OpenDNS on your Ubuntu Computer through DDclient in just 6 steps – Tutorial

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1 – Why should I change DNS?

As for Wikipedia, DNS (Domain Name System) is “a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network… …it translates more readily memorized domain names to the numerical IP addresses needed for the purpose of locating and identifying computer services and device with the underlying network protocols. By providing a worldwide, distributed directory service, the Domain Name System is an essential component of the functionality of the Internet “.

You “use” them in any moment, every time you are in front of a computer but usually you don’t consider to directly manage or change them because you think that it is not worthy to do anything with them.

On the contrary, you know that many different online companies offer dedicated DNS addresses you can use to substitute the default DNS addresses provided by your ISP.

So, at this point, your main question is “Why should I change DNS on my route or my computer”?

For example, for one or more of these different reasons:

– to have a chance of a possible increasing of speed and reliability when you surf Internet;

– if you want to delegate to a third “professional” part some security tasks (e.g. third party security filtering to protect yourself against phishing or viruses);

– acces websites that are normally geoblocked by commercial policies/agreements or censorship imposed by Governments;

– parental monitoring if you prefer to have a rough idea of what websites your children visit or if you whant to filter some specific contenents.

2 – Choose a reliable DNS provider

If you decide that you want to try a different DNS provider you need to choose a reliable one. A quick search on Internet will help you to find the most appropriate DNS Provider for your needs.

In this specific case we are examining how to configure the DNS from OpenDNS.com so, if you want to test it, you have to sign up for a free account on opendns.com or simply copy the DNS addresses you find in the bottom right of their homepage or sign up for a OpenDNS.com free account. In the last case, you have the possibility of monitoring your traffic in a professional statistical way and probably you will satisfy one or more of the reasons that may explain your choice to use different DNS.

3 – Install DNS from OpenDNS on your router

If you want to use OpenDNS on your LAN you have to configure the router through the its configuration interface. The way you can do this varies from one router to another but in all the popular models you will easily find a specific sub-menu where you could activate the “use predefined DNS” option compiling the two addresses provided by OpenDNS.

In this way all your LAN traffic will be pipelined through OpenDNS and you will not need to singularly configure each computer you have.

Image from: oriental-press.com

4 – Install DNS from OpenDNS on your Linux computer

4a – Preliminary configuration.

The problem with opendns.com is that it doesn’t provide an official tutorial to correctly install its DNS on a Linux machine. For this reason you can follow this brief notes that I wrote after installing it on a Ubuntu 14.04 LTS Ubuntu computer.

Go to the OpenDNS.com support page dedicated to the installation on Ubuntu and follow their instructions:

https://support.opendns.com/entries/38042814-Ubuntu

I exactly followed all the instruction till the point 8 but, when I had big problems when I typed:

sudo ifdown eth0 && sudo ifup eth0

because this message appeared:

ERROR unknown interface eth0=eth0

The matter is that my ethernet is really named eth0 (I double checked using the commands ifconfig and netstat -r -n) but it was not possible to operate on it.

To solve this problem I used the Poorak’s Blog suggestion and I had to open the interface file via Terminal with:

sudo nano /etc/network/interfaces

– or if you prefer:

sudo gedit /etc/network/interfaces

and manually add these lines:

auto eth0

iface eth0 inet dhcp

then I restarted my networking

sudo /etc/init.d/networking restart

References: [SOLVED] ERROR unknown interface eth0=eth0 on ubuntu

4b – Install DDclient on Ubuntu if you have a dynamic IP

Normally the Internet Service Provides provides a dynamic IP to users that may change over time. So, if you don’t want to pay more to obtain a static IP, you need to install a software that could constantly communicate your actual IP address to OpenDNS.com. In my case, I dedcided to install DDclient to be able to continue to properly use the OpenDNS.com services.

To install DDclient I preliminarly had to install coreutils through Terminal:

sudo apt-get install coreutils

and the required SSH and SSL sockets:

sudo apt-get install ssh libio-socket-ssl-perl

and finally the DDclient:

sudo apt-get install ddclient

At this point you manually edit the configuration file:

sudo nano /etc/ddclient.conf

(or, if you prefer sudo gedit /etc/ddclient.conf)

typing:

##
## OpenDNS.com account-configuration
##
use=web, web=myip.dnsomatic.com
ssl=yes
server=updates.opendns.com
protocol=dyndns2
login=opendns_username
password=opendns_password
opendns_network_label

where:

– ‘opendns_network_label’ is the label given to the network you’re updating in your account.

If you have spaces in your network label, replace them with an underscore ( _ )

You can find the network label in the Settings Tab of the OpenDNS Dashboard.

– the login is your email address with OpenDNS

– the password is your opendns password.

“If you have special characters in your password wrap the password in single-quotes ( ‘ ).

If there are any single-quotes in your password, put backslash ( \ ) before the single-quote to escape the character”.

References:

– Using DynDNS Protocol to Replace OpenDNS Updater

– How To Install DDclient On Ubuntu (ssh, ssh-perl, ddclient)

5 – Start OpenDNS and DDclient on your Ubuntu computer

At this point you have all the elements to start so you can open a Terminal and type:

sudo /usr/sbin/ddclient chkconfig ddclient on && sudo /usr/sbin/ddclient service start

On the other side, if you want to check the status of DDclient, you will type:

sudo /etc/init.d/ddclient status

References: opendns on Ubuntu via ddclient

6 – Configure Linux OS to start DDclient at boot on Ubuntu

On Ubuntu is really simple to configure DDclient to start at the computer boot. You have to open the Session and Startup manager through the desktop Dash. Now you are able to Add a specific command to the Application Autostart menu to run DDclient at the boot:

sudo /usr/sbin/ddclient chkconfig ddclient on && sudo /usr/sbin/ddclient service start

If you are configuring OpenDNS through DDclient on a different Linux distribution you can google the right tutorial or follow the guide created on aboutLinux.info.

At this point you will automatically use OpenDNS on your Ubuntu computer.

References: Using DynDNS Protocol to Replace OpenDNS Updater

Start 2016 with a bunch of unusual Linux OS!

linux-distributions-to-look-forward-in-2016

What’s better than testing? For me nothing!

For this reason, let me introduce some “unusual” Linux distribution proposed by Jesse Afolabi @Jesseflb via Techmint.

VeltOS and PapyrOS are based on Arch but the last one is in its pre-alpha testing so it’s not suggested for beginners.

Moreover, we may decide to begin 2016 with Korora that is still one of my favorite projects also after so many years since the first release.

Last but not least, we have Solus OS 2 that it is not the most Linux distribution I tested but it is stable and really well built.

Happy 2016!

3 things you need to remember when Upgrading to Fedora 23 as for the Unicmen’s instructions

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The upgrade from Fedora 22 to Fedora 23 is not automatic, as usual in my Fedora experience, but it is really simple to manage if you follow the path suggested by Unixmen.

There are few things you need:

– connect your laptop to the power plug (if you use a laptop);

– a couple of hours (something more or less depending on your CPU, RAM, Internet connection speed, etc..);

– few lines of commands on the Terminal

Image from https://fedoramagazine.org

The upgrading process is well structured and to start it you need to launch Terminal and upgrade the native Fedora Fedup with its new version that now is integrated into DNF:

dnf upgrade

Then you have to install the DNF plugin:

dnf install dnf-plugin-system-upgrade

and finally you can start the “core” part of the upgrade just typing:

dnf system-upgrade download –releasever=23 –allowerasing –best

Where:

– allowerasing will continue the upgrade also in presence of any “old” (not yet upgraded) third part repositories that normally would have completely stopped the main upgrading process

-best is a verbose mode in case of unsatisfied dependencies

After a while, depending on your Internet connection speed, you will be able to conclude the upgrade typing:

dnf system-upgrade reboot

Your laptop will reboot and the upgrade starts.

From now you spend more than 40 minutes waiting and answering to few easy questions that the OS asks you to solve some configuration matters.

The length of the waiting time depends obviously on the CPU, the RAM and the type of Hard Disk installed into your PC.

That’s it!

Link

Image: Jack Wallen

Ubuntu GNOME 15.10: The perfect Linux desktop distribution

“Username is not in the sudoers file. This incident will be reported…” How to add a specific user to sudoers on Linux

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Sooner or later, if you use Linux and you prefer Terminal to GUI you will stumble on this message:

Username is not in the sudoers file. This incident will be reported

The first thing to clarify is that the “incident” will never be reported outside your computer but in the auth.log file. But if you have previously configured your Linux OS to send these kind of logs to you by email, you receive an alert about.. your own activity with sudo…

In any case, to solve the above mentioned specific sudo matter, use Terminal and type:

sudo gedit /etc/sudoers

At this point the text file “sudoers” will be opened and you will be able to modify it using e.g. gedit.

Obviously you can use another text editor you prefer as, for example, nano. In this case the command will be:

sudo nano /etc/sudoers

Now you have to peer into the text and find the “#User privilege Specification” section and add the command:

your-username ALL=(ALL:ALL) ALL

where ALL=(ALL:ALL) ALL stands for: allow the specific user (your-username) to access all the terminals, as if he/she were any other user, and allow him/her to execute the full range of commands.

And you will obtain something similar to this:

# User privilege specification
root ALL=(ALL:ALL) ALL
your-username ALL=(ALL:ALL) ALL

Try it! (..if you need…)

——————-

References:

https://help.ubuntu.com/community/RootSudo

Accessing Devices without Sudo

If you liked YUMEX, don’t miss YUM EXTENDER (DNF) for Fedora 22

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If you are one of them (like me) that prefer to manage and/or install software through an easy to use GUI, don’t forget to migrate to the new version of the “old” YUMEX.

Open your favourite Terminal and type:

su

dnf install yumex-dnf

Follow the instructions that appear on the screen and enjoy the new DNF GUI manager for Fedora 22.

Hibernate for Ubuntu

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Since the Ubuntu 12.04 LTS the hibernate icon disappeared as possible option at the shutdown. It is not a big loss if you are not used to use (or overuse) it as I often do. Personally I think that the hibernate feature is really useful when you want to freeze your computer maintaining all the windows -and the work- you are working on at a precise moment.

Ubuntu decided to “cut” this particular command from its GUI because it registered a remarkable number of problems caused by hardware conflicts in modern computers.

If you use Ubuntu and you think that hibernate could till be useful for you (especially during busy working days), it is possible to insert again this specific feature as GUI on your Desktop.

First of all you have to test if your computer contains the right hardware for “hibernate” so open Terminal and type:

sudo pm-hibernate

The computer will hibernate itself but you have to reboot it to understand if hibernate worked properly in your case.

I hope (as it was for my PC) that all has gone well. In this case you can start to create the dedicated icon on your upper bar.

Before of starting it’s necessary to understand that the hibernate command will use the SWAP partition to save your temporarily data. Usually it is recommended to have a SWAP partition with, at least, the double of space of your RAM.

So I suggest to install Gparted to check the SWAP space and, only if necessary, increase your SWAP partition reducing the primary partition. Please, do this only after you safely backup all the data in your computer because this procedure could be risky if you are doing it for the first time and you have not enough experience:

sudo apt-get install gparted

Open a Terminal and install gedit and gksu (if you don’t have them already installed on your machine) typing:

sudo apt-get install gksu && sudo apt-get install gedit

Then type:

sudo gksu gedit /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla

Now a blank gedit document, named enable-hibernate.pkla will appear on your screen.

Copy and paste the following text to “compile” it:

[Enable Hibernate]

Identity=unix-user:*

Action=org.freedesktop.upower.hibernate

ResultActive=yes

Save it and reboot your computer.

A new icon will appear on the right corner of the upper bar. When you click on it, a Terminal window will appear asking for the system password. Type it and click on Return and your PC will immediately hibernate.

Good busy working days!

—————-

References:

http://www.howtogeek.com/113923/how-to-re-enable-hibernate-in-ubuntu-12.04/

http://askubuntu.com/questions/49095/how-do-i-add-more-swap-easily-so-that-i-can-hibernate-my-laptop#49162

https://help.ubuntu.com/community/SwapFaq

http://askubuntu.com/questions/29783/so-what-is-the-reason-behind-the-claim-that-you-need-at-least-as-much-swap-area#29809

Bodhi: a less known but powerful Linux distribution

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If you are looking for a light Linux OS for your computer you can test Bodhi Linux. This specific Linux version, based on Ubuntu, utilizes the enlightenment graphical interface. For this reason Bodhi is particularly indicated also to give new life to computers with no updated hardware.

The graphical interface is really “zen” or rather clean, easy to navigate but complete. We tested the 32 bit version and it was a smooth experience also if we used a single core pc with 2 GB of RAM.

Before testing Bodhi you have to keep in mind that this Linux OS is really user oriented. It means it has just some few pre-installed programs and so you are free to customize it as you prefer. Last thing to remember is that Bodhi is a semi-rolling distribution ans so it will be updated in occasion of Ubuntu Long Term Releases (LTS). Try it, it is worth a chance!