How To Create A Screencast In GNOME 3

GNOME 3 has an inbuilt software that allows you to record your desktop. This makes it very easy to create a screencast in GNOME 3. Here is how you do it ...
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Switching To Linux - Tale Of A Former Mac User Who Is Also A Musician

Switching to Linux is easy for most of us. You just have to download and burn a Linux distribution and boot your computer with it. If the Linux distribution you have chosen is a modern one, then you can finish installing it on your machine in 6 steps or less.

However, if you rely on your computer for a living, then you need to do some preparations prior to making the switch. Kim Cascone, an experienced and gifted musician and composer had been using an Apple PowerBook to compose music. When his PowerBook G4 exhibited signs of age, he did a quick fact check and found that he could save as much as $3000 (which includes the machine and the software costs) if he switched to Linux.
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How To Build An Open Source FreeNAS Server

Now a days, most people have more than one computer at home. If not, then there are a multitude of devices such as - laptop(s), WiFi enabled cell phones, network aware audio & video devices, and game consoles.

If that is true for you, then it is a fair guess that you will have your own private store of music, movies, and video games, not to speak of other valuable files which are scattered across any of the above mentioned devices you own.
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Screencast - Install OpenSolaris in VirtualBox

Installing OpenSolaris on your machine may require some gentle hand holding if you are a first time user of the operating system. More so if you are thinking of installing OpenSolaris in VirtualBox. But help is at hand. I came across an exceptionally done screencast which walks you through installing and configuring VirtualBox in Windows, and then installing OpenSolaris in VirtualBox.
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Google portable device runs Debian Linux

The portable device I am talking about is the T-Mobile G1 Android cellphone. Android is a software stack for mobile devices that includes an Operating System, Middleware and key applications. Presumably, the T-Mobile G1 contains an ARM EABI architecture which is supported by Debian.

So a group of people (hackers) set out to install Debian on their T-Mobile G1 Android phone. The end result, at the least, is quite interesting. They have succeeded in running a full fledged Debian OS on their G1 Android cellphone at the same time, retain all the features which allow it to function as a cellphone such as receiving and making calls.

Read a detailed writeup on the steps needed to install Debian on a TMobile G1 Phone at the following website. AndroidFanatic.com has released a Debian installer script for your Android cellphone which you can download here.

Also watch the following video which shows Debian running on the Android G1 cellphone.

The art of disk partitioning explained

Now a days, most computers include hard drives with 100s of gigabytes of space. In such a scenario, it is inevitable that you partition the hard drive to optimize the use of space. Dividing your hard drive into individual partitions for your operating system, programs, data files, music, and images provides better organization and, most important, much better data safety in the event of a drive crash.

This article explains why it is prudent to partition your hard drive to more manageable chunks.

On the other hand, if you already have a well partitioned hard disk and you wish to combine two or more chunks of disk partitions to save your data, instead of deleting a partition, you can always use logical volumes which form a layer above the physical partitions and which can span multiple partitions. Read more about how you can create logical volumes and resize them in Linux. The article - how to manage disk space with LVM also makes an interesting read.

A guide to Ubuntu customization

Would you like to customize your Ubuntu to look like Windows Vista ? Or may be you are more of an Apple fan boy with not enough moolah to buy yourselves a Mac. Either way, there is hope around the horizon. The beauty of Linux is that it is so customizable, you can make it look and feel like any other operating system.

Fig: Ubuntu in Windows Vista theme

If you are by any chance running Ubuntu and wish to customize it to your hearts content, then head over to tuxenclave which features a detailed Ubuntu customization guide. Besides that also take a look at how you can transform KDE to look like MacOSX.

Install Linux on Sony Playstation PS3 - a collection of tutorials

Do you own a Sony Playstation (PS3) ? If you do then here is some good news for you. Now it is possible to install your favorite Linux distribution on a Sony PS3. Then you may ask, what is so unique about PS3 and why should I bother installing Linux on a machine which is primarily designed for playing games, right ?

You see, PS3 has the PowerPC architecture underneath its hood. More importantly, it is powered by IBM's Cell processor. The same processor which will be powering future IBM mainframes. So if you own a PS3 why not harness this awesome power of its processor to run Linux ?

Sony has provided an open platform for Playstation 3 where you can get details of installing another OS on your Playstation.

Apart from the above link, I came across a number of resources which provide step by step explanation of installing a specific Linux distribution on the PS3. They are as follows :

• Install Fedora on PS3 [ Read the article ]
• Install OpenSuSE on PS3 [ Read the article ]
• Install Ubuntu on PS3 [ Read the article ]
  
• Install Gentoo on PS3 [ Read the article ]

The only prerequisites for installing Linux on your PS3 is that the distribution you choose should have a CD image available for the PowerPC architecture. Other than that, I think the steps are more or less the same.

Install multimedia codecs in Ubuntu 7.10 Gutsy Gibbon in 2 easy steps

Ubuntu is a fantastic Linux distribution and its development is right on track. While I have had issues in running Ubuntu 7.04, Feisty Fawn on my machine, the latest release namely version 7.10 (Gutsy Gibbon) turned out to be a heck of a distribution. Not only does it work flawlessly on my machine, the Ubuntu developers have also incorporated a number of features which brings it at par with or in some cases even excels Mac OSX in functionality and ease of use.

But at the same time, unlike many other Linux distributions (read Mandriva et al), the Ubuntu developers have not succumbed to providing the proprietary codecs and drivers out of the box. In fact, they have walked a fine line by making sure the distribution remains Free as in freedom, at the same time have made it very simple for people who want to surely install any proprietary drivers for their machine.

For example, here is how you can install all the proprietary multimedia codecs automatically on your machine running Ubuntu Gutsy Gibbon.

First thing you have to do is to navigate in the Gnome panel to "System -> Administration -> Software Sources" and enable all the additional repositories namely main (which should already be enabled), universe, restricted and multiverse. Truth be told, you need select only the multiverse repository but while you are at it, you might as well enable the rest of them too.

Once you have done that, navigate to your video or audio file and try playing it in Totem which is the default multimedia player for GNOME. When you open the media file in totem, it will notify you that it can't find the necessary codecs to play the file and will offer to search for and download the necessary files. It will then start downloading the missing pieces and install them. That is it. You have finished installing the codecs necessary to play your multimedia file.

Fig: Enable all additional repositories

Fig: Totem asks you whether it should search for the necessary codecs to play the media.

Fig: Totem searching for required multimedia codec packages

Fig: It provides a list of packages which contain the required files

Fig: Asks for confirmation.

Fig: Totem playing the movie after it finished installing the required codecs.

As a side note, I have found that this is the same process that is followed by the Windows media player when it can't find the necessary codecs. But there is a significant difference though, in Ubuntu Gutsy Gibbon, this process works flawlessly where as in Windows, it gives an error ;-).

Alternately, if you do not want to go through the above process (though I wonder why), you can also install all the multimedia codecs by firing up a terminal and running the apt-get command as follows :

$ sudo apt-get install gstreamer0.10-plugins-bad gstreamer0.10-ffmpeg gstreamer0.10-fluendo-mp3 gstreamer0.10-plugins-ugly

You must be wondering, if there are bad and ugly gstreamer plugins there should be the good ones too right ? Well the good gstreamer plugins are installed by default on your Ubuntu machine and so you need not install them manually.

Finally, for the brave at heart, you can also install the multimedia codecs manually as explained in this article.

Nmap explained from an Ethical Hacker's View

Nmap (Network MAPper) is a network scanner written by Gordon Lyon. It is a free and open source tool and is available at insecure.org with versions for Windows and Linux and is ubiquitous in its use.

Nmap can be (and is) used to for instance, scan for open ports on a remote server, to detect the OS run on the server, what all services are running on the remote server and so on.

Many of us might have run the TCP SYN scan which require root privileges and the TCP connect scan which can be run even as an ordinary user. But there is much more to the usage of nmap tool.

Kirby Tucker at ethical hacker has written a very informative article which provides inside knowledge about the usage of nmap as well as what each command accomplishes.

In part I of this tutorial, he explains no less than 13 different scans you can run using the nmap tool. And at the end he also demonstrates how you can glean information by running nmap in conjunction with wireshark (an open source network protocol analyzer). A really interesting read for all aspiring system administrators.

Update (September 06 2007): It seems the publishers of the article have run into some copyright problems and have temporarily taken the resource down till the problems could be ironed out.

In the meantime, a comprehensive resource on nmap which you will find really helpful is the book titled - "Secrets of Network Cartography: A Comprehensive Guide to nmap" authored by James Messer which you can freely read online. You can even download a PDF version of the book for a nominal price.

Howto: Build an selinux policy the Red Hat enterprise way

Red Hat / Fedora has now got GUI tools to help edit and create SElinux policy files. And it is much more simpler to create a custom selinux policy in Red Hat Enterprise Linux.

In this detailed article, Dan Walsh gently walks you through the policy module creation process.

A lot of people think that building a new SELinux policy is magic, but magic tricks never seem quite as difficult once you know how they’re done. This article explains how to build a policy module and gives you the step-by-step process for using the tools to build your own.

Read more on a step by step guide to creating an selinux policy module explained by Dan Walsh.

Update: Also check out this PDF presentation on Managing Red Hat Enterprise Linux 5 which also contain information on SELinux.

Set up an Apache web server cluster in 5 easy steps

A server cluster is a group of independent servers that are managed as a single system for higher availability, easier manageability, and greater scalability.

In a Web server environment, server clusters can be defined in two basic ways:

Active/Active

• There are multiple independent, redundant servers
• The load is distributed through round-robin DNS
• The load is balanced by a load-balancing solution
  

Active/Passive

• Multiple servers are configured to provide a service
• Only a single server provides the service at any given time
• Other servers serve as hot-spares in case of a server (service) problem or a site hosted on the servers suddenly start getting load spikes such as when being slashdotted.
  

Now a days, many shared web hosting providers are turning to a web server cluster solution over managing individual web servers on independent machines. Clustering is said to provide some respite to the performance issues.

Eli M. Dow and Frank LeFevre, both, Software Engineers at IBM have written this insightful albeit rather technical article which explains how to setup an Apache web server cluster in 5 easy steps.

From the article ...

Spreading a workload across multiple processors, coupled with various software recovery techniques, provides a highly available environment and enhances overall RAS (Reliability, Availability, and Serviceability) of the environment. Benefits include faster recovery from unplanned outages, as well as minimal effects of planned outages on the end user.

To get the most out of this article, you should be familiar with Linux and basic networking, and you should have Apache servers already configured. Our examples are based on standard SUSE Linux Enterprise Server 10 (SLES10) installations, but savvy users of other distributions should be able to adapt the methods shown here.

Learn how to set up an Apache web server cluster in 5 easy steps.

SSH tutorial for Linux

SSH stands for Secure SHell. This is similar to telnet but with the difference that while telnet sends all your data including your password as plain text across the network, SSH sends everything in encrypted format. This means that it is well impossible to snoop at your data or passwords while it is in transit across the Internet or network.

Over a period of time, I have written a couple of articles on this blog related to SSH. Today I came across a very well written tutorial on using SSH by Mark Krenz. He explains the concept of SSH, generating public private encryption keys, forwarding an X11 session on top of SSH, TCP forwarding, SOCKS5 proxying and so on. A very good article worth spending ones time to read.

Related articles:

• How to setup SSH keys and why ?
• SSH - Secure SHell explained
• Integrating SSH in GNU/Linux

How to find out if your Linux machine has been hacked ?

It is very rare that your Linux PC which you use as a Desktop will get compromised especially if you do not run any services like a web server, mail server and so on. More over many modern Linux distributions like for example Ubuntu, targeted at the end user ship with all the ports closed by default. And others like PCLinuxOS bundles with it a robust firewall. So it makes the job of an intruder all the more harder to crack into your machine.

But suppose after all the precautions you take, some resourceful cracker succeeds in finding a loophole and hacks into your machine, how do you detect that your machine has been compromised in the first place?

Lars has written a step-by-step process by which he ascertains that a Linux server run by his friend has been compromised by an intruder. His findings throw light on what you can expect and the steps to take when you are suspicious of getting your machine rooted.

The server was running a fairly updated Ubuntu 6.06 LTS. He goes on to conclude that the compromise could have been caused by :

1. An exploit unknown to the public.
2. A user accessing this server from an already compromised host. The attacker could then sniff the the password.
   

Read this very interesting article which throws some light on the actions of a hacker.

Installing Vmware on Ubuntu Using the Canonical Repository

This is a step by step howto to install and setup a Vmware server on a machine running a server version of Ubuntu. The idea is to install a linux server to run a Vmware Server and host the virtual machines without installing X windows and all the associated bloat. This ensures that the maximum amount of memory on the server machine is made available for the virtual machines.

Check out this well illustrated howto by Matthew Browne to learn how to achieve this.

Managing disk space with LVM

Now a days, when one installs Linux on ones machine, in more cases than one, there is a trend to create a logical volume and create the file system on this volume rather than creating the file system in individual partitions. I have myself created logical volumes on one of my machines running Linux.

Logical volumes have their own advantages in that one can grow or shrink a volume without any loss of data. And that makes it much more flexible than creating file systems directly in partitions. Another advantage is that one can bundle multiple hard disks together to create a single logical volume such that the operating system sees only one volume even as the data resides across multiple physical hard disks. In a previous post titled "Resizing Logical Volumes", I had briefly put down my experiences in create logical volumes in Fedora Linux.

Now Bryce Harrington and Kees Cook have come together to write this very informative article titled 'Managing Disk Space with LVM' which clearly explains the ins and outs of creating, modifying and deleting logical volumes in Linux which makes an interesting read.

Usually, logical volumes are more desirable where there is a constant flux in the amount of data in storage devices such as a machine running as a file server or a database server and so on. But even home users could benefit from creating logical volumes if they are in the habit of saving lots of data on their hard disk like games, movie clips,songs... and see their disk space shrinking at a fast pace.And if the hard disk fills up, the procedure is as simple as attaching a second hard disk and then extending the logical volume on the first hard disk to include the new one. But if you go the LVM way for your desktop, just make sure that the /boot directory resides in a physical partition of its own instead of the logical volume as boot loaders like GRUB and LILO don't support LVM yet.

Building a bittorrent box

Ross explains how to setup a bittorrent box which remotely downloads the files and serves it to ones local machine. This quite exhaustive article explores how to do it using a combination of a headless PC (ie a computer without a monitor) running Ubuntu, OpenSSH (openssh-server), a vnc server (tightvnc-server) , a VPN client, Samba and of course a bittorrent client.

The bittorrent client he has used to download the files to his headless server from the internet is Azureus which is a java based client and so I suppose you also have to install Java runtime environment in Ubuntu.

He also explains how to setup autofs to configure the machine so that drives or partitions can be mounted on the fly by Ubuntu when you try to connect to that partition from your laptop or another machine on your network.

As to why he has written this tutorial, this is what he has to say (and I quote) ...

While most of our time on the Internet is spent IM’ing, e-mail, or just browsing the Web, you may run in to situations when you need to do some powerful file transfers. If you use a laptop, you’re use to getting up, suspending your laptop, and running out the door all of the time. But, sometimes you know you just need something dedicated to get work done. You’ll need a solution to retrieve files and serve data when you need it.

In this guide, you’ll learn how to set a small headless Ubuntu server used to retrieve BitTorrent files, while even saving them to a external USB hard drive that can be disconnected on the go. You even discover how to remotely administer your server from the Web using SSH, VNC, and an inuitive HTML UI, while being able to retrieve files while you’re away from home.

This tutorial takes for granted you have a spare computer laying around. Building a computer is out of the scope of this article.

Do read this very informative article written by Ross to understand how to build a bittorrent box.

Getting access to gmail accounts of the deceased

Do you have a gmail address ? And do you store sensitive information in your gmail account which you have received from your contacts ? Then you (or rather people close to you such as your family) might be interested in knowing the ways in which someone can gain access to your account in the event of your demise.

You have to follow a number of procedures to eventually gain access to someones gmail account. This article explains what it takes to make google reveal the password of a gmail account not your own.

While this is not strictly related to Linux, I am sure you will find this information useful as I have because, I have an email address at gmail.com.

QEMU-Puppy - A portable personal computer on a USB stick

A few months back, I bought a 4 GB Kingston USB memory stick. It cost me around 1800 Indian Rupees (In US dollars it comes to just over $45). My idea was to use it partly as a data storage where I could keep files as backup and to use a part of the USB stick to install Linux.

The USB stick initially had only a single FAT 32 partition. So I repartitioned the USB stick to two 2 GB partitions each, both having FAT 32 file system. And in the first partition, I decided to install Linux. I went through the process and copied the distribution of my choice to my USB stick partition and even made it bootable using syslinux - which is a boot loader for Linux operating system. But as luck would have it, my computer refused to boot from the USB stick complaining there was no boot loader on the USB stick.

Later I came to know that syslinux has a limitation of working only if the partition is less than 1GB size and my USB stick had a partition of 2 GB. I didn't get the time to go back and try it out again. Perhaps I will try it some time soon on a 1 GB partition.

Today I came across this quite exhaustive but very informative article titled - "QEMU-Puppy - A Personal Portable Computer" written by Erik Veenstra where he explains how to turn your USB stick into a personal portable computer. He uses Puppy Linux (A very good minimalistic Linux distribution) and QEMU for the same. Erik walks one through the installation of QEMU and Puppy, to booting, configuration of various parameters, some tips and tricks that will save your time and a bit of Puppy Linux internals. All in all a very interesting article and a project worth trying out.

A collection of tips for people new to BSD

The first time I was introduced to FreeBSD - a BSD variant, I came away really impressed. In my opinion, from an end user's perspective, the only difference between a BSD and Linux is the difference in licencing. If you setup two machines - one running FreeBSD and the other running a Linux distribution with both having a KDE or Gnome desktop and ask a neophyte to point out which is which, there is a good chance that he will consider them both as running one and the same operating system. So whether you choose Linux or BSD depends largely on your tastes.

On the down side, the BSD variants fall far behind when you compare the size of their community with respect to that of Linux which commands a community which is many times that of the BSDs. But if you consider the ratio of knowledgable people to newbies, the BSD's fare better.

If you are a potential BSD aspirant and wish to try out any of the BSDs which include FreeBSD, PC-BSD, OpenBSD, NetBSD and DesktopBSD, then you might find the resource page put up by Daemon News quite helpful. It contains lots of tips to carry out tasks which a neophyte in BSD might initially find insurmountable.