Ubuntu - Boot failure ending with initramfs prompt


Yesterday was a fearful day ... when I switched on my laptop, it was totally stuck during the boot process, leaving me with a scary initramfs prompt.

Obviously, this has happened just after I had finished mounting 3 hours of video with OpenShot Video Editor and unloaded almost 100 pix from my digital camera !

I was able to get the grub menu, but whatever kernel version I was selecting, I was always ending up with the following screen :

mount: mounting /dev on /root/dev failed: No such file or directory
mount: mounting /proc on /root/proc failed: No such file or directory
Target filesystem doesn't have /sbin/init.
No init found. Try passing init=bootarg.

BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash)
Enter 'help' for a list of built-in commands.

I first though that my hard disk had died. But after a second though, as I was getting grub menu and ending on a initramfs prompt, the boot sector has been read properly. So hard disk was not in a completely pathetic condition.

In fact, the problem was coming from a corruption of my root filesystem. Because of that corruption, the root filesystem couldn't be mounted at boot.

This short article explains how to recover from such a scary situation and how to get your computer back to a working condition.

Even if tested on Ubuntu, it should be applicable to any Linux based computer with a ext3 or ext4 root filesystem.

Read more: Ubuntu - Boot failure ending with initramfs prompt

Ubuntu - Configure Wifi connexion thru Command line Tools


Nowaday, interface like Network manager makes wifi connexion setup a very simple task.

But in some specific cases (ubuntu server, ubuntu minimal media center, ...), you may need to setup you WEP or WPA wifi connexion directly from command line, without using network manager.

This article explains how to fully configure a WEP or WPA encrypted wifi network from a console terminal, using only command line tools.

It has been tested on Ubuntu Precise 12.04, but it should work on any modern Ubuntu or Debian flavored distro.

Read more: Ubuntu - Configure Wifi connexion thru Command line Tools

Ubuntu 12.04 - HP 2510p laptop (wifi, fingerprint, performance and power management)

HP 2510p

The HP 2510p is a 12.1” screen notebook designed for heavy duty and security.

Ubuntu Installation is very simple on this laptop, as it integrates some very standard components.

But, if you want to be able to fully exploit this laptop possibilities, you still need to do some specific configurations for :

  • Core 2 Duo CPU power management capabilities
  • Mobile Intel GM965 Express chipset
  • Intel Pro 4965 wifi adapter
  • AES2501 fingerprint sensor

This article will explain how to configure Ubuntu Precise 12.04 to fully use the HP 2510p laptop hardware.

It will also help you to tweak your HP 2510p for better overall performances and battery power management.

Read more: Ubuntu 12.04 - HP 2510p laptop (wifi, fingerprint, performance and power management)

Gnome Shell - Customise your SSH terminal per Host basis


If you are a sysadmin, your desktop must be filled with SSH consoles, allowing you to supervise and administrate a lot of different servers. And there is nothing more similar to a console than another console.

As all these console are the same, there is a real risk of error, typing some commands on the wrong server ...

Nowadays, the standard Gnome Shell terminal is providing a begining of solutions with the support of profiles. So, with the help of these profiles, you can easily change the title bar, background color, background image or text color of your consoles. Your consoles can be customised for every host, but you have to select the profile once the console is opened.

Why not to automatised the process ?

This article explains a solution to select automatically a profile according to the SSH host. The main principle of the proposed solution is to :

  • create one SSH configuration for each host
  • create one Gnome Terminal profile per host
  • use a helper script to detect the host and to launch the terminal with the right profile

To make it simple, when you will type custom-ssh -e "ssh server1"  you will launch gnome-terminal SSH console to server1 host using server1 profile.

The strengh of this solution is that it will be integrated with SSH Search Shell Extension, which is a fantastic productivity tool available under Gnome Shell. It allows you to launch your SSH console by just typing the first letters of the host to administrate.

It has been tested under Ubuntu Precise 12.04, but it should work with any Linux distribution using Gnome Shell 3.x.

Read more: Gnome Shell - Customise your SSH terminal per Host basis

Ubuntu - Resume your computer from any USB device (keyboard, mouse, remote, ...)


With the arrival of Gnome Shell, one major step has been taken : by default you can't switch-off your computer !

In fact, the only menu available is Suspend. You have to press ALT at the same time to see the Switch-off menu. You will find lots of topics about this strange evolution on the net, with lots of furious people who still want to keep the power of switching off their computer.

But, if you think twice about it, suspend / resume is one of the revolution of modern appliances : who is still switching-off a TV set, a video player or an ADSL box ?
Almost nobody ! Now, you suspend it from your remote. So why not to handle your favorite computer the same way ?

usb-symbol Even if it is consuming a little bit of power, suspend state is having a very strong advantage : it takes almost no time to resume to working condition.

Who is ready to wait for 1 minute or more to check his mails, when 5 seconds are enough to resume a computer with thunderbird already open ?

Under Ubuntu, the only trouble is that your USB input devices (keyboard, mouse, MCE remote, …) are not fully configured by default to be used to resume from a suspend mode.

This guide will explain how to configure your USB input devices to be able to wake-up your suspended computer. As a result, you will be able to wake-up your Ubuntu computer with :

  • a simple key press on your keyboard
  • a click on your mouse center button
  • the power button of your MCE remote

It has been written on a Ubuntu Precise 12.04, but should be applicable with any Linux flavor using a kernel version prior to 3.10.
As USB power management has changed drastically in kernel 3.10 +, this article is not applicable for kernel 3.10+.

Read more: Ubuntu - Resume your computer from any USB device (keyboard, mouse, remote,...)

Ubuntu 12.04 - Revo 3610 as a XBMC Media Center with TV and Remote

 dropcap-xbmcNowadays, Linux can be a fantastic welcoming OS for a very complete Media Center. In term of functionnalities, here is what you can expect :

  • silent & low consumption system
  • possibility to use a MCE Remote
  • suspend/resume from the remote only
  • ability to play HD movies (720 & 1080)
  • DVB-T functionnality, including HD channels
  • recording possibility for DVB-T
  • access to all video, photo & music from a network share
  • access to any type of media on USB key or APN

After reading this list, you can say : Ok, very well, but why not to use a distribution like Openelec ?

Answer is simple : geekitude ... is an attitude ! Why let others handle things that you can handle directly by yourself.

So, here are the installation steps to convert a very small & silent nettop into a full featured digital Media Center using a standard Ubuntu Precise 12.04 platform.

Read more: Ubuntu 12.04 - Revo 3610 as a XBMC Media Center with TV and Remote

Thunderbird - Fully sync with Gmail services (Email, Calendar and Contacts)

Thunderbird for Gmail

Nowadays, more and more smartphones and tablets are running Android OS, which is tightly linked to google Gmail services.

These devices are designed to be fully synchronised with main Gmail services :

  • email
  • calendar
  • address book

On the other end, you are having a computer at home were you are also handling emails, calendar and personal address & phone book.

This guide will explain how to fully setup your Thunderbird client to get it fully synchronised with your Gmail account for all associated services.

With this setup, you will be able to handle your emails, calendar events and personal address book entries from any of your Android device (smartphone and/or tablet) and your personal computer.

And ... all of them will always be fully synchronised. Whatever you do on one side will be forwarded to all others.

All this guide has been tested on a Ubuntu desktop, but it should work on any Linux or Windows Thunderbird client.

Read more: Thunderbird - Fully sync with Gmail services (Email, Calendar and Contacts)

Ubuntu 10.04 - TrendNet N150 (TEW-648UB) wifi adapter on Lucid


TrendNet N150, also referenced as TEW-648UB, is one of the smallest and cheapest USB Wifi adapter available.

But this Wifi adapter is not working Out Of the Box under Ubuntu Lucid 10.04 LTS.

NetTrend N150 adapter is powered by a Realtek RTL8192SU chipset, which is recognised by the latest 2.6 kernel, but needs a firmware which is not provided by the standard Ubuntu Lucid packages.

trendnet-n150-tew648ubThis article will explain the easy steps to make it work under Ubuntu Lucid.

It has been tested on Lucid x86 (32bits), but there is no reason that it should not work with Lucid AMD64 (64bits).



Read more: Ubuntu 10.04 - TrendNet N150 (TEW-648UB) wifi adapter on Lucid

Ubuntu 12.04 - Stabilize your camcorder video with MELT and Vid.stab


Since availability of Ubuntu Xenial 16.04, this procedure is obsolete and is not updated.
Please use Ubuntu 16.04 - Rotate & Stabilize your video with MLT and Vid.stab instead.

Nowadays, street video shooting is becoming a reality.
Who is not having a smartphone, a point-and-shoot camera with video capabilities or even a HD camcorder ?

These devices are affordable, light-weight, very compact and easy to use. Whatever happens around you, you are able to record it on the spot. But, on the other end, as these devices are compact and light, they are not very steady. Your recordings tend to be shaky !

Till date, there was no simple solutions under Linux to stabilize (unshake) videos. One of the first one I used was transcode with vid.stab plugin. This stabilization plugin is very efficient. But the transcode tool is giving lots of trouble as soon as you want to encode your resulting video to h264. In fact, the interface between transcode and ffmpeg is type of 'broken'.

Short time back, the MLT framework has integrated a port of vid.stab stabilization plugin. That is a very good news as MLT framework provides a command-line tool melt which interfaces very well with FFmpeg libraries for h264 encoding.

This article will explain how to easily post-process any video file to stabilize (unshake) it. It will use :

  • latest version of MELT, a command-line tool from MLT framework, which comes now with vid.stab stabilization filter
  • latest version of FFmpeg to re-encode the resulting video with h264 codec and aac audio

It will explain 2 different approaches :

  • stabilization thru command-line
  • stabilization directly from Nautilus, thru a Nautilus script
Read more: Ubuntu 12.04 - Stabilize your camcorder video with MELT and Vid.stab

Joomla - Cross-browser mp3 playback with audio.js library


If you need to publish some music on your site, you know how difficult it is to provide a cross-browser solution. Either your audio files will be embedded in a Flash stream and it won't be compatible with all IOS devices (iPhone, iPad, ...) or it will be compatible with HTML5 format and it won't be compatible with older browsers (IE8, Firefox 3, ...).

Hopefully, audio.js is there to fulfill all these needs. It is a fork of video.js, targeted on audio content in mp3 format. In fact, it's a drop-in javascript library that allows HTML5's tag to be used anywhere, with a Flash fallback for browsers not understanding HTML5. It is focused on mp3 format, due to its universality.

As a result, it is compatible with about 99% of the world browsers ! This seems to be the ultimate solution to publish audio content.

This article will explain how to allow you to easily publish some mp3 audio files on your Joomla site thru the audio.js library. It is using the standard <audio> tag and it has been tested on iPhone, iPad, Firefox, Android, ...

It has been designed on a Debian server with a Joomla 1.5 site, but it should be compatible with any Joomla 2.5 site as well.

Read more: Joomla - Cross-browser mp3 playback with audio.js library

Ubuntu - Tweak Firefox for speed and SSD disk


Firefox is a very powerfull and versatile browser, but it has the tendancy of doing a huge amount of disk write accesses.

If you hold a modern computer with very fast hard disk, it's no problem.

But if your hard disk is slow or if it is a SSD drive, you then need to minimize to a maximum all the disk write access, in term of responsivness and durability.

This article will explain how to optimize firefox following two main directions :

  • minimize the write accesses (very interesting for SSD drives)
  • tweak generic parameters for performance boost

Its first effect will be a huge disk write access reduction and ... a real boost in terms of performance !

So lets start to tweak your firefox parameters to rediscover your surf experience.

Read more: Ubuntu - Tweak Firefox for speed and SSD disk

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