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How to fix Virtualbox error “Kernel driver not installed (rc=-1908)” on Ubuntu

Virtualbox I recently installed the latest version of Virtualbox (4.3.12) by downloading the deb files from virtualbox.org on Ubuntu 14.04. The installation goes fine, but when trying to run Virtualbox, it reports the following error. Kernel driver not installed (rc=-1908) The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing '/etc/init.d/vboxdrv setup' as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles...
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CentOS 6.5 vs. CentOS 7.0 NAS Performance Comparison

After years of development, RedHat finally released the next major version of RedHat Enterprise Linux (RHEL) v7. RedHat Enterprise Linux is an enterprise-grade Linux distribution, which is frequently used in corporate data centers as an operating system for NAS storage devices. From the performance point of view, the new Linux kernel and the new default file system may have a significant impact on a NAS storage device and therefore it is very important to understand how the newly released RedHat Enterprise Linux version 7.0 compares to the last stable version 6.5.

 

http://www.flexense.com/centos6_vs_centos7_nas_performance.html

 

 

How To : Install NVIDIA 331.89 (Stable) Graphics Drivers in Ubuntu/Linux Mint Systems

The latest version of Nvidia Graphics driver for Linux which is Nvidia 331.89 has been released and is available for download. It comes with plenty of fixes and changes. This article will guide you to install Nvidia 331.89 in Ubuntu and Linux Mint systems.

Fixes

  • Added support for the following GPU:
      GeForce GT 730
  • Fixed a race condition in the NVIDIA kernel module that caused some GPUs to sporadically become unresponsive.
  • Updated the error reporting in the NVIDIA kernel module to include the GPU serial number, when available, in error messages written to the system log.
  • Fixed a bug that caused blank screens when transforming or rotating displays in an SLI Mosaic layout.
  • Fixed a bug that corrupted certain software rendering on 32-bit systems.

Read more on YourOwnLinux

 

CentOS 6.5 vs. CentOS 7.0 NAS Performance Comparison

After years of development, RedHat finally released the next major version of RedHat Enterprise Linux (RHEL) v7. RedHat Enterprise Linux is an enterprise-grade Linux distribution, which is frequently used in corporate data centers as an operating system for NAS storage devices. From the performance point of view, the new Linux kernel and the new default file system may have a significant impact on a NAS storage device and therefore it is very important to understand how the newly released RedHat Enterprise Linux version 7.0 compares to the last stable version 6.5.

 

http://www.flexense.com/centos6_vs_centos7_nas_performance.html

 

 

How To : Install NVIDIA 340.24 Graphics Drivers in Ubuntu/Linux Mint Systems

  The latest version of Nvidia Graphics driver for Linux which is Nvidia 340.24 has been released and is available for download. It comes with plenty of fixes and changes. This article will guide you to install Nvidia 340.24 in Ubuntu and Linux Mint systems.

Fixes

  • Fixed a bug that prevented 3D Vision stereo and ultra low motion blur modes from working on G-SYNC capable monitors in some cases.
  • Fixed a bug that caused the "Allow G-SYNC" checkbox to be displayed in nvidia-settings even if the GPUs in the system are not capable of G-SYNC.
  • Fixed a kernel crash when running some applications with IOMMU functionality enabled.
  • Fixed a floating point exception in the OpenGL driver when running "Risk of Rain" under Wine.
  • Made various improvements and corrections to the information reported to GL applications via the KHR_debug and ARB_debug_output extensions.
  • Fixed a bug that caused GLX applications which simultaneously create drawables on multiple X servers to crash when swapping buffers.
  • Updated nvidia-settings to report all valid names for each target when querying target types, e.g. `nvidia-settings -q gpus`.
  • Added support for controlling the availability of Fast Approximate Antialiasing (FXAA) on a per-application basis via the new __GL_ALLOW_FXAA_USAGE environment variable and the corresponding GLAllowFXAAUsage application profile key. See the README for details.
  • Fixed a bug where indirect rendering could become corrupted on system configurations that disallow writing to executable memory.
  • Updated the nvidia-settings Makefiles to allow nvidia-settings to be dynamically linked against the host system's libjansson. This option can be enabled by setting the NV_USE_BUNDLED_LIBJANSSON Makefile variable to 0.Please note that nvidia-settings requires libjansson version 2.2 or later.

Read more on YourOwnLinux

 

How To : Install/Upgrade to Linux Kernel 3.15.5 in Ubuntu/Linux Mint Systems

   "The Linux Kernel 3.15.5 is now available for the users and all the users of 3.15 kernel series must upgrade", announced Greg Kroah-Hartman.This Linux Kernel version comes with plenty of fixes and improvements. This article will guide you to install or upgrade to Linux Kernel 3.15.5 in your Ubuntu or Linux Mint system.

 

More details on YourOwnLinux

 

Devscript: Local Development Environments on Linux with just one Command

Did you ever have that experience when you’re setting up a new Development Environment when you’ve just formatted your system or when you somehow screwed up your Configuration?.

Or Maybe you just don’t want to google for an hour every time you set this stuff up?

Let me show you what it is like with the usual installation:

sudo apt-get install apache2

sudo apt-get install php5

sudo apt-get install mysql

sudo apt-get install php5-mcrypt

php5enmod mcrypt

Arghhh!!!!!

We are really smart Developers, We shouldn’t need to do this stupid stuff.

So, How do we fix this?

You don’t need to, Its already fixed.

Have a look at this little tool called Devscript.

Its Local Development Environments with just one Command.

Don’t believe me? Just have a look at this little Video.

DevScript from Nihal Sahu on Vimeo.

Cool, Right?

Anyway ,Try Using DevScript for your projects too.

The Official Github Page

 

How to check processor and cpu details on Linux

Processor/Cpu details The details about the processor that we shall be talking about include, number of cores, availability of hyper threading, architecture, cache size etc. To find these details about the cpu on your system can be a bit difficult because the way different commands check them. The commands that we are going to use include lscpu, /proc/cpuinfo and lstopo (hwloc). They report detailed information about the cpu cores/processing units. The examples...
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Easy File Comparisons With These Great Free Diff Tools

File comparison compares the contents of computer files, finding their common contents and their differences. The result of the comparison is often known as a diff.

diff is also the name of a famous console based file comparison utility that outputs the differences between two files. The diff utility was developed in the early 1970s on the Unix operating system. diff will output the parts of the files where they are different.

Linux has many good GUI tools that enable you to clearly see the difference between two files or two versions of the same file. This roundup selects 5 of my favourite GUI diff tools, with all but one released under an open source license.

<A HREF="http://www.linuxlinks.com/article/2014062814400262/FileComparisons.html">Full article</A>

 

Web Development Tools for Linux & How to Install Them

Often due to some restrictions by the web development company, most of the web developers are forced to use free open source platforms such as Ubuntu. For such developers, it becomes headache to work without the tools that are mandatory and used for developing a website. However, there are some similar tools available for Linux that can be used in the web development.

In this article, we are going to see a good list of Web Design / Development tools for Linux. Additionally, the installation steps given for each tool are specially for Ubuntu, however it should also work on Debian operating system.

GIMP

GIMP is an open source web designing tool and an alternative for Adobe Photoshop. Personally, I believe that it lacks some of the features as well as needs to be polished, however, once you are familiar with it, it will become a good alternative to Photoshop. This tool can be used for basic image manipulation, also may be decent at the more advanced stuff too, depending on the skills of the web designer.

Gimp

How to install Gimp on Linux

sudo apt-get install gimp

INKSCAPE

Inkscape is an open source vector editor. Though the UI looks ugliest for some people, however I found this tool very powerful and packed with more great features as compare to Adobe Illustrator.

inkscape

How to install Inkscape on Linux

sudo apt-get install inkscape

IMAGEMAGICK

ImageMagick is basically a command line editor, especially useful for resizing, sharpening, adding filters and watermarks on images in bulk. Check the official website of ImageMagick for more instructions.

How to install ImagicMagick on Linux

sudo apt-get install imagemagick

GEDIT

gEdit assists in the tasks of reading, printing and editing of texts, simply and easily. Simple, yet full of features with tools such as copy, cut, paste, undo and redo, settings fonts and colors, the software has all the common features of text editors. This does not mean that Gedit is a basic editor, with several other features. Possessing highlight setting for various programming languages ​​such as C, C + +, Java, HTML, XML, Python, Perl, among others, gEdit can be a good choice as a text editor for programming and development on Linux platform.

gedit

How to install gEdit

sudo apt-get install gedit

SUBLIME TEXT 2

The Sublime Text is a code editor which supports several languages ​​such as HTML5, CSS, PHP, ASP and Python, for example. The software has a very clean interface, and the black background of the screen does not bother reading anything. Two of the best features of it are the Multiple Selections and Command Palette, which allows you to access any menu item or let you open any document in just few key strokes.

Subime

How to install Sublime Text 2 on Linux

Check the installation steps here.

SASS

Sass - another method to write CSS. With Sass, we have more freedom to treat the styles applied concepts of OO programming. It uses the Ruby language to interpret their .scss files / .sass or compilers installed on your system (Mac, Windows, Linux) to transform .scss / .sass on. Css.

How to install Sass on Linux

In order to install Sass on a distribution of Linux, you'll require to install Ruby first. To install Ruby and then Sass, follow the steps given here.

GCOLOR2

Gcolor2 is tool that translates any shade of color, so you can use it in your image editor. It displays the color code in hexadecimal, their levels of saturation, hue, and RGB values ​​and opacity. This software also has feature to save the colors, name and code.

gcolor2

How to install gcolor2 on Linux

sudo apt-get install gcolor2

FILEZILLA

FileZilla is an application intended for users who want to connect to servers via FTP communication protocol. With it you can upload and download files from the web easily and quickly. It will run on almost anything such as OSX, GNU/Linux and Windows.

filezilla

How to install Filezilla on Linux

sudo apt-get install filezilla

DRUSH

Drush is a simle command line shell and scripting interface developed for Drupal. It allows you to download, enable, disable, uninstall, update modules/themes/profiles/translations via the command line in a very simple way (apt-get style).

How to install Drush on Linux

sudo apt-get install drush

Once you have installed it, simply update it to the latest version using the following command.

sudo drush dl drush --destination='/usr/share'

PHPMYADMIN

PhpMyAdmin is a an excellent set of PHP scripts in a form of browser base interface to manage MySQL Server. It allows you to create, edit, view and delete databases.

phpmyadmin

How to install phpmyadmin on Linux

sudo apt-get install phpmyadmin

TASKSEL

The tasksel is one of the most efficient terminal based application that installs multiple software at once on Linux distributions such as Debian, Ubuntu, Mint, etc...

tasksel

How to install Tasksel on Linux

sudo apt-get install tasksel

VIRTUAL BOX

VirtualBox is a more reputable options for operating systems in virtual machines emulation. With it you can run a system within another, like Ubuntu (or any other Linux distribution) on a Windows PC or Mac, and vice versa.

How to install Virtual Box on Linux

sudo apt-get install virtualbox

APACHE BENCH

The ApacheBench Apache is a software used for testing the performance of web servers, regardless of the server used. This is very useful for comparing the performance of different configurations, but can not always show the reality of the environment.

How to install Apache Bench on Linux

sudo apt-get install apache2-utils

LYNX

Lynx is a terminal-based web browser, used to display text only, ideal for systems based console or with few graphics. It is useless for web designers, but good for developers to test the code after writing.

How to install Lynx on Linux

sudo apt-get install lynx

Hope you find these tools helpful.

 

Setting up VPN on Linux

There is definitely a growing trend of people trying out Linux operating systems. The motivation might be the fact that they are free and generally considered superior to Windows when it comes to security and stability. People who want to give Linux a fair shot generally go with Debian-based forks like, Ubuntu, Linux Mint etc.

Although installing some of the most common software like, Skype, Web browsers, Music players are pretty easy using the software repositories, it could be quite intimidating for a newbie to configure VPN or install a new printer if it doesn't work out-of-box.

A VPN comes very handy to protect one's personal information, gain access to geo-restricted content -- for instance, one can use a US VPN to gain access to services like Spotify and Netflix, to secure their internet connection when using unprotected public networks. However, if one looks for the right tutorial or ask for help in discussion boards, one would realize the fact that setting up things on the popular Debian-based distributions is quite easy. There are 2 types of VPN solutions, OpenVPN and PPTP VPN. Today we are going to see how to setup VPN with PPTP on Ubuntu and its derivatives.

If you know a thing or two about Linux, it would only a few minutes to setup VPN. If you are beginner, stop bitting your nails, you are going to do just fine if you are a good at following instructions.

Server side setup

The server will be responsible to assign IP addresses to all the client machines in the network, be it Linux, Windows or Mac clients.

- 1. The very first thing is to install the PPTP package on your server. One can simply use the standard "apt-get" command to install. It is advisable to update the repositories first. Use the following commands. It will only take a few seconds for the installation to complete.

sudo apt-get update
sudo apt-get install pptdp

- 2. Now you will have to edit the pptd.conf file. The file resides in the following path, "/etc/pptpd.conf"
If you have GUI you can do it with your favorite text editor (e.g. Gedit).

sudo gedit /etc/pptpd.conf

Or you could use "nano" to edit the file right from the terminal.

sudo nano /etc/pptpd.conf

If you have not used nano before, you might as well check out this discussion on Ask Ubuntu [http://askubuntu.com/questions/54221/how-to-edit-files-in-a-terminal-with-nano] for help.

- 3. You need to add the following two lines to "pptpd.conf."

localip 172.20.0.1
remoteip 172.20.0.100-300

What does these lines do? The VPN server will use the localip inside the VPN and an IP with in the range 172.20.0.100 to 300 (e.g., 172.20.0.120, 172.20.0.124, etc.,) will be assinged to the clients that connect to the server.

- 4. The next step is to add new users. You will have to use "nano" or a text editor or Gedit like you did with editing the pptpd.config file above. The file will have all the information about users and is stored in the following file, "/etc/ppp/chap-secrets"

Edit this file to add new users. You will have the enter certain details in the right order for this to work. First you will have to enter the client's name, followed by the server, the password and IP address.

So a couple of new client added to the VPN might look like this.

computer1 pptpd password *
computer2 pptpd password *

You can either use a specific IP address, but it is better to use asterisk, which means that any IP address in the range assigned could be used to login.

- 5. This step is optional, but is advised to assign a DNS server. There are several free DNSs out there, the 2 most popular are, OpenDNS and Google's DNS.

If you want to use OpenDNS, you should use these IP addresses 208.67.222.222 & 208.67.220.220. If you would like to use Google's DNS, you will have to use the IPs 8.8.8.8 and 8.8.4.4. To use OpenDNS you can add these lines to the file.

ms-dns 208.67.222.222
ms-dns 208.67.220.220

- 6. Almost everything on the server side is done. Now it is time to wake the daemon. To start PPTPD, you will have to use the following terminal command.

service pptpd start

- 7. Now you need to setup proper forwarding. This time you will have to edit the file "/etc/systl.conf"
There should be the following line in this file.

net.ipv4.ip_forward = 1

If it doesn't exist, copy paste this into the file and save the file and update it using the command,

"sysctl -p"

- 8. Finally if you wish the clients to communicate with one another, you will have to add the following rules.
# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE && iptables-save

In the above rule, you will have to replace "eth0" with the internet connection that is used by the server. You can use the commands, iwconfig and ifconfig to figure this out.

# iptables --table nat --append POSTROUTING --out-interface ppp0 -j
# iptables -I INPUT -s 172.20.0.0/20 -i ppp0 -j ACCEPT
# iptables --append FORWARD --in-interface eth0 -j ACCEPT

The above rule also requires you to use the correct internet connection like for the first rule. That's it everything on the server side has been configured and clients could now handshake with the server now.

Client side setup

It really doesn't matter what operating system the clients run. You can find tutorials to configure Windows and Mac OSX on the internet. There are even services like Switch VPN, that can help you connect you Android device to the VPN server quite easily. However, here we are going to see how one can easily setup a Debian-based client for VPN.

- 1. The client should have pptp installed. We have already done this step on the server. You will just have to do this again on your clients with the following terminal commands on Debian-based distros.

sudo apt-get update
sudo apt-get install pptp-linux

- 2. Now you will have to load the ppp_mppe module, which could be triggered with the following command.

modprobe ppp_mppe

- 3. Create client configuration file in the following directory (/etc/ppp/peers/). You can name this file whatever you want. But you will have to remember this file name to connect to the VPN server.

pty "pptp --nolaunchpppd"
name computer1
password password
remotename PPTP
require-mope-128

If you had named this file "vpncomputer1", you should use the following command to connect to the server.

pppd call vpncomputer1

- 4. Finally for proper routing, you will have to execute the following line.

ip route add 172.20.0.0/20 dev ppp0

The above steps can use used several times to add multiple clients to the server.

 
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