Ubuntu on Subhadip's Blog

Format USB drive after installing Debian from it

Sat, 01 Dec 2018 00:00:00 +0000

If you have used an USB drive to write iso images to before installing Debian or recent versions of Ubuntu, here are the steps to reclaim it after installation is over.

Open a terminal and list the available device names using the following command:
```
lsblk
```
which should show you an output like the one below:
Identify the device name of your USB drive. Extreme caution should be taken while at it because wrong device names can potentially wipe your entire hard disk. In this case, the USB drive that we want to format is sdb.
Writing the iso image to the USB drive has made it a read-only device. To change it back, the partition table needs to broken. Issue the below command after replacing sdb with the device name identified in the previous step:
```
sudo dd if=/dev/zero of=/dev/sdb bs=1M && sync
```
This step might take some time to complete depending upon the size of the USB drive. So be patient. When it is over, you should see an output like the below:

VLC Player not playing nice with Radeon?

Mon, 22 Jan 2018 00:00:00 +0000

If you are on Ubuntu 16.04 using radeon open source driver for your graphics card and having issues with playing mp4 or mkv files with VLC media player then read on. If you are not sure what graphics driver is in use in your system, paste the below line in Terminal.

lspci -v -s lspci | awk '/VGA/{print $1}'

And check for the below line in the output:

Kernel driver in use: radeon<br />

The issue occurs as soon as you open a media file of type mkv or mp4 with VLC media player. Immediately after opening, it crashes silently. But if you check the /var/log/syslog, you should be able to see segmentation fault messages.

Accessing Mysql database installed in an LXD container

Sat, 20 May 2017 00:00:00 +0000

This is my second post on LXD containers. Sometimes, using a container is a cleaner way to install and use applications for a number of reasons:

You can install packages from any version of any distribution. That means, even if you are using an LTS release of Ubuntu like me, you don't necessarily have to stick to an older version of a package. Or if some package is only supported on rpm based distributions, you don't need to worry about it.
You can go ahead and completely uninstall/reinstall it at any time without worrying about residual files or configurations.
You can roll back to a previous state in no time if something goes wrong unexpectedly (lxd snapshots!)
And then there is the security perspective also (lxd containers are secure by nature).

Last weekend I tried running mysql database from a local container and connect to it from my local system. Here's how:

LXD Containers - First Experience

Sun, 02 Apr 2017 00:00:00 +0000

Lately I have been playing around with LXD containers and I must say that I am quite impressed with it. LXD is the virtualization technology that can be used to run a Linux container on a Linux host using the same kernel as the host.

Well, it's a little difficult to grab the idea at first. Unless of course you interacted with it before. You can think of it as a virtual machine that you run using VirtualBox or VMWare on your Linux or Windows host machine but the difference is that when you run a virtual machine, you are running a separate kernel inside the virtual machine but in this case, you are fooling the guest OS running inside the LXD container into thinking that it's running its own kernel whereas it's just using the same kernel running on the host OS. And the result is that you get an isolated container with a much smaller memory footprint and little overhead compared to a full blown virtual machine.

Automated Package Installation and Configuration Script for Ubuntu

Thu, 29 Dec 2016 00:00:00 +0000

In my last post, I discussed about how I created my first Amazon EC2 instance and ran our Java web server on it. One of the most important things that I have realized over the years is that if you work with a small group of developers, you ought to think about automating certain jobs like testing, deployment, setting up server etc. So that you can concentrate on the real work rather than spending valuable time in doing repetitive tasks. The benefit against spending extra time in writing scripts may not be prominent at first, but over time you will realize the gain in terms of person hours and headaches saved because of the automated scripts.

Running Java app server on AWS EC2 Ubuntu instance

Sat, 26 Nov 2016 00:00:00 +0000

Today I will be writing about setting up an Ubuntu instance on the Amazon AWS cloud and running a Java web application on it. We are working on a hobby project that has its back-end written in Java. The app back-end was first hosted on Heroku but due to some issues, we decided to move it to Amazon AWS. I was given the responsibility to set up our server. This was the first time I had an opportunity to work with Amazon AWS. But it turned out to be quite fun.

Automatically dim display when switching to battery power on Ubuntu

Wed, 21 Sep 2016 00:00:00 +0000

I bought a Dell Inspiron laptop recently which came with Ubuntu 14.04 preinstalled. Something I noticed with the factory Ubuntu 14.04 image was that some of the settings were tweaked to work better with the laptop. One fine example was that the laptop display would automatically dim when I switched to laptop battery from the power supply. It would again go back to full brightness once I connected the adapter back.

The Perfect Javascript Editor

Sun, 28 Aug 2016 00:00:00 +0000

Being primarily a Java developer using Eclipse IDE, there are two things I always look for in any IDE - content assist/code completion and syntax checking/highlighting. While the latest version of Eclipse (Neon) has made a lot of improvements over the previous versions in terms of the JSDT plugin for Javascript developers, it's far from perfect. The syntax highlighting works upto some extent but the content assist is still very primitive if at all useful.

SSH into CentOS 7 guest from host machine using VirtualBox

Sat, 14 May 2016 00:00:00 +0000

I have mostly used Ubuntu and Debian-based distributions till now which means the other side of the Linux world, where the RHEL based distributions reside is still a grey area to me. Recently I needed to install CentOS server in VirtualBox to test something out. But soon I found that it's a little cumbersome to work in the VirtualBox vm window because I can't copy/paste texts normally to/from the VirtualBox as I can do in Terminal and I can't cycle through the open windows in my guest machine using Alt+Tab when I am using the vm. So I decided to ssh to the CentOS guest from the host machine and work from the host Terminal instead.

Installing qemu with kvm and virt-manager

Sat, 02 Apr 2016 00:00:00 +0000

I have used Oracle Virtualbox before. It has an easy and intuitive UI, supports all the features I needed and is open-source. But this time I decided to use another widely recognized virtualization solution on Linux, qemu, along with kvm.

First of all, let me give some brief idea about qemu, virt-manager and kvm. Qemu is the software which can be used to install and run a guest OS on top of the actual OS to put it in a very simple way although it's much more powerful than that. It can be compared to Virtualbox except that qemu itself does not have a UI, instead it's a command line utility. Virt-manager is some thing that provides a GUI to qemu. Together virt-manager and qemu can be thought of as the Virtualbox. On the other hand, kvm is the Linux kernel module that can help qemu execute the virtualized instructions directly on the CPU which can improve the performance greatly. This is to be kept in mind that qemu can run even without kvm but the speed will be much slower.

Coding with Go - Part 1 : The Workspace Setup

Sun, 27 Dec 2015 00:00:00 +0000

Go (sometimes referred as Golang) is the system programming language from Google which is my new interest these days. Some of my favourite points about Go so far:

It's a compiled language and I like compiled languages. To somebody who has used C/C++ and later Java for programming, this should come as no surprise.
It has fairly easy syntax and it's not a lot different from C which definitely helps to learn the language quickly.
It can be used like a scripting language.
It has a fairly large built-in package collection.
It has first class Linux support.

Here's what I did to get my workstation ready to code with Go:

Developing Node.js with Atom Editor

Sun, 27 Sep 2015 00:00:00 +0000

Recently I have been playing with Node.js and for every developer, getting the perfect IDE/Editor and setting up the workspace is very important. Here's how I got my set up ready:

I am using Xubuntu 14.04.3 LTS. So the steps that I am going to share will work in any of the Ubuntu flavours.

1. Installing Node.js: Node.js is already there in the default Ubuntu 14.04 repository and the version is 0.10.25. If you need more updated version, you have 2 ways. You can either download it from the official Node.js site, or you can follow this tutorial and add a third-party repository or use nvm to get it installed. In the first case, it will not be auto-updated though. However, I chose to use the default repository version as I didn't see the point in going through all these hassle unless I specifically want a feature that is only available in the newer versions.

[Solved] Flash player in Google Chrome keeps getting stuck under Ubuntu/Linux

Sat, 28 Mar 2015 00:00:00 +0000

Although I use both Firefox and Chrome on my Linux box, for playing any flash video (yes, I know flash is going to go away and I hate it too but for the time being, it's still here), sometimes Chrome is the only option as the Flash player plugin for Linux is very old and many websites do not support it already (Chrome separately packages it's own flash player which is not dependent directly upon your platform (which means it is available for Linux also) and it's version is regularly updated, if you didn't know already).

[Solved] Cheese Webcam Booth not displaying video from Webcam in Ubuntu

Sun, 15 Mar 2015 00:00:00 +0000

I own a Logitech c170 web-cam which has very good Linux support. I bought this web-cam almost 2 years ago and at that time, it worked like a charm on Ubuntu 12.04. I stopped using the web-cam over a year ago and I almost forgot about it. A few days ago, I had an interview on Skype and as my phone front camera does not work well with Skype, I needed to take this one from my Desktop. So I took the web-cam and plugged it in to my computer running Ubuntu 14.04 (yes, I upgraded), launched Cheese (comes pre-installed on Ubuntu 14.04) hoping everything would work just as before. But to my surprise, even though I could take photos using Cheese, I could not see the video stream. Here's what I did to solve the problem:

Install Subeclipse subversion plugin in Eclipse + Ubuntu

Wed, 14 May 2014 00:00:00 +0000

Subclipse is an Eclipse Team Provider plug-in providing support for Subversion within the Eclipse IDE. Installing Subeclipse plug-in in Eclipse running on Ubuntu (or any other Linux distribution) is a little more complex than on win-32 platform. You need to install an additional package that contains the JavaHL binaries. To install Subeclipse, follow the below simple steps:

1.Go to Ubuntu Software Center and install the below package.

libsvn-java

2.Note the installed version of the above package.

Permanently change Duplex settings and Network card speed in Ubuntu

Sun, 11 May 2014 00:00:00 +0000

Users of Alliance or similar broadband services might have noticed that their network connection would sometimes get dropped while on Ubuntu or the network speed is somewhat less than what is advertised. The solution for this is that you need to change the duplex setting of your network connection. Don't freak out yet, it's not as hard as you might think. Follow the below simple steps:

1. Get the desired duplex settings from your service provider. In this case, we will assume that it's "10 duplex half". Replace it with the appropriate speed in your case.

[SOLVED] SVN/JavaHL version problem in Ubuntu 13.04 with Eclipse Indigo

Sun, 13 Oct 2013 00:00:00 +0000

I upgraded my Ubuntu from 12.04. Eclipse 3.7 with Subclipse 1.6 was installed in 12.04. Now after upgrading to 13.04, after I start Eclipse and synchronize my project with the repository, it throws the error message: "Incompatible JavaHL library loaded. 1.6.x or later required."

Possible reason: libsvn-java is needed to be installed in Ubuntu in order to make SVN work in Eclipse. The installed version in Ubuntu 12.04 was 1.6 as far as I remember. But after upgrading to 13.04, the libsvn-java version was also upgraded to 1.7. But the version of Subclipse that is compatible with libsvn-java 1.7 is Subclipse 1.8.

Not Switching to Kubuntu

Sat, 22 Jun 2013 00:00:00 +0000

I have been an Ubuntu user (Linux in General) for long enough time. When I was in college, I would live boot different distributions of Linux just for trying out, eager to see what new desktop effects they might have added, what the defaults applications were. But after I graduated from college and joined work, I would get little time to do all those stuffs. So I settled for just one and also I needed a stable environment. Currently I am using Ubuntu 12.04 and today after getting back from work, I felt like I got bored with Ubuntu. So I thought, what the hell, I should try out KDE and if I like then I might even replace Ubuntu. So I downloaded Kubuntu and ran it on a USB stick. I installed it in one of my spare partition also, to give it a fair chance to impress me. And it really did impress me. I liked the desktop environment, I liked the KDE default application set. They were designed very carefully. The applications launched way faster than they would in Ubuntu. But I don't know why, my eyes were still searching for the same fonts and the same look they were used to see on Ubuntu. Also I missed all those keyboard shortcuts that I enjoy using while on Ubuntu. So I rebooted back to Ubuntu. I fixed the Grub2 which was replaced by Kubuntu Grub2 with the grey screen. But I could not re-enable the auto-hiding of Grub2 while booting. I guess I will find some way to do that. But now I am feeling quite sleepy.