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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Adobe AIR 2 Beta for Linux Released

Adobe AIR 2 beta (runtime and SDK) has been simultaneously released for Windows, Mac, and Linux. AIR 2 builds on the success of AIR 1 by giving developers new capabilities and even tighter integration with the desktop.
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Clipboard Managers in Linux

A clipboard manager is a computer program that adds additional functionality to basic clipboard usage. The main tasks of a clipboard manager are as follows :

1. To store data copied to the clipboard so that it can be pasted after closing the host application of the data copied.
2. To store and retrieve multiple clips from the clip history available – any number of times.

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Adobe's free gift to unemployed developers

Are you an unemployed developer? Did you get the pink slip because your company found it costly to retain you after the economic down turn? Then cheer up because Adobe has decided to provide some succor by releasing it's flagship product Adobe Flex Builder Professional for free. The catch is that - of course, you have to be unemployed and, you can use the software only for personal use to improve your programming skills.
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Upgrading Sun Java System Directory Server Enterprise Edition to version 6.3

Introduction

As part of my network infrastructure I also deployed an instance of Sun Java System Directory Server Enterprise Edition (JSDSEE from now on). I chose to download and install it with the Sun Java Enterprise System (JES from now on), which at the time of writing has reached version 5 update 1, which ships JSDSEE 6.2.

Installation of this and other products with the JES installer went smooth on my Solaris 10 update 5 instances and the services were deployed, configured and up and running in a question of minutes.

Some weeks ago we had an abrupt server shutdown the same day I was adding some entries in the LDAP server. When the server went up it was no big surprise to me discovering that the LDAP database was corrupted and the only options I had was restoring from a backup, which I had obviously done. Again, the service was restored in a matter of minutes.

However, I discovered by chance that JSDSEE 6.2 is affected by a bug that, in certain conditions, may result in data loss and database corruption. The bug report can be examined at Sun Solve website at this address: JSDSEE bug #6642430. The bug has been resolved but it implies upgrading JSDSEE from version 6.2 to version 6.3.

Getting the software

When it comes to getting the software, you are presented these options:

• Sun Java Enterprise System distribution
  
• native packages distribution
  
• zip distribution

The JES installer installs its products with native packages and I usually prefer to use this method rather than install zip distributions and carefully tracking down the details about every software I installed. In this case is that the native package distribution is a patch to apply to a previous JSDSEE installation.

Differences between the distributions

The differences between the distributions are described in the document Sun Java System Directory Server Enterprise Edition 6.3 Administration Guide. It's not obvious, because the documents I read first, Sun Java System Directory Server Enterprise Edition 6.3 Release notes and Sun Java System Directory Server Enterprise Edition 6.3 Installation guide, tell nothing about this.

Java Enterprise System distribution

Basically, the JES installer is a native package distribution, but it still delivers just JSDSEE v. 6.2, and you can only rely on a patch to upgrade JSDSEE to v. 6.3. The JES installer, also, does not provide the Directory Server Resource Kit, which is provided by the zip distribution. The JES installer is a GUI tool which facilitates the installation of the components delivered with JES and it also facilitates the shared components used by the products in the suite. The JES installer must be run as root because the products are installed as native packages.

Native patches

The native patches must be run as root, too, and let you upgrade your existing JSDSEE installation to version 6.3. As I'll tell in the following sections, these installation method is not supported on Solaris Express or OpenSolaris.

Zip distribution

The zip distribution is a non-root self-contained distribution which can installed by anyone. Multiple version of the product can then be installed at the same time. The drawbacks of this kind of distribution is that the system administrator is responsible of having these services start at system boot and that whoever installs them must keep a detailed log of every installed product.

Test run on Solaris Express Community Edition

Before upgrading a production server, I always test the installation on another machine. Unfortunately I had no such machine at hand so I decided to test the installation on Solaris Express Community Edition (SXCE from now on) build 103. I'm using SXCE because the JES installer was not running properly on OpenSolaris 2008.05 so I switched some development machines to SXCE to be able to use these kind of Sun distributions.

The JES installer went smooth on SXCE and I also replicated the LDAP database on the test machine. Unfortunately, when it came to run the patches, I was caught in a sort of patch hell because I found no way to install the required patches on it without having patchadd complaining about packages' versions or dependent patches. After losing and entire night trying, I decided to switch to Solaris 10.

Patching JSDSEE 6.2 on Solaris 10

This time, everything went absolutely smooth. I just followed the recommendations on the Sun Java System Directory Server Enterprise Edition 6.3 Installation guide and I just ran the following commands in this order (be aware that these patch numbers are relative to Solaris 10 x86/AMD64). The list of patches is available here.

Stopping the services

After patching, all the services must be shut down. First I stopped the Directory Server Control Center

# dsadm stop /var/opt/SUNWdsee/dscc6/dcc/ads

the I stopped the JSDSEE instance I previously registered with SMF. This step depends on your installation.

Upgrading shared components

I installed the following patches taking care of following the special instructions included with them (if your system is not Solaris 10 AMD64 please check this):

• 119811-05
• 125953-18
• 119044-03
• 123896-05
• 125446-12
• 119214-17 (be aware that this patch number depends on the version of some system packages. Check documentation before installing)

Installing the patches to version 6.3

The patches to install on Solaris 10 AMD64 are these (be aware that the localization patch must be installed before the JSDSEE v. 6.3 patch):

• 125938-06 (localization patch)
• 125278-07

Conclusion

After installing these patches and restarting the JSDSEE services, everything was up and running. Since now on, I'll always have a Solaris 10 installation to test these kind of setups because it's not the first time I have problems with Sun packages on SXCE or OpenSolaris.

Google Chrome internet browser loses its beta label

After a testing phase unusually short for Google's standards, the Mountain View internet browser has already lost its beta label. The announcement was published on 12/11/2008 with an official google blog post. Google promises improvements in many areas including:

• Stability and plugins: many bug fixes were related to media playback, especially in the case of video playback. This new version of Google Chrome should deliver a much better user experience and a higher availability of plugins for the browsers. To say the truth, indeed, plugins were something that the few Google Chrome users were really missing.
• Performance: the already fast Google Chrome and its V8 JavaScript engine has been improved and benchmarks show an 1.4x improvement
• Bookmarks and privacy: this new version of the browser deliver a less geeky configuration user interface. Privacy and security related options are now grouped together with detailed explanations for the novice. Data import from other browsers' configuration sets have been improved. Bookmark management has been improved too, with a particular attention for bookmark bulk management, in the case you have tons of bookmarks to import and export

I'm very curious and I'll have a Google Chrome test drive on a Windows image running on Sun xVM VirtualBox. Google has also announced an extension platform and support for Mac OS X and Linux, but I don't think this will help seeing Google Chrome running on Solaris very soon...

Tip : Quickly open special locations in Nautilus

It is really amazing that in many ways than one, it is the open source software developers who are in the forefront of innovation the most. If you ask me, one reason may be because they listen to the end users more than any proprietary software developers. Secondly, the open source programmers are not tied down by the bureaucratic hurdles that weigh down on their closed source counterparts. But in my opinion, the most pertinent reason is that creating open source software is purely a labour of love - a love of coding and creating something of real value to themselves and to others.

Take Nautilus file manager for instance, it has a plethora of hooks built in which allow a user to navigate to different locations by just typing in a name. For example, to get network locations, you type in network:/// in the location bar of nautilus.

There are a number of such shortcuts which allow an end user to navigate to different locations with ease. Shankar has compiled a set of nautilus shortcuts which throw light on the in-built versatility of Nautilus.

Portable Apps - Carry all your favorite Open Source applications where ever you go

Recently while visiting a friends house, I ran into a situation where I had to use his computer. His computer is a rather old one which he has seldom maintained properly. He still has Windows 98 loaded on it. The very same Windows OS which came pre-installed on his computer when he bought it a couple of years back. And most applications including the web browser (IE) have not been updated. In fact the web browser he has on it is IE 4.0. And as you will know, IE 4.0 does not have good CSS support and so render most websites poorly. And on top of all that, he is so tech phobic that he was not inclined to allow any other software on his machine.

That was when I felt the need for a solution where in I could use a standalone version of my favorite applications. And after some googling, I came across this unique website called portableapps.com which has a collection of many Open Source and GPLed software which I use on a daily basis.

The idea is that you can use these applications without installing on the hard disk. For instance, faced with a situation such as mine, you can easily carry all the applications on a USB stick and then just plug in the USB stick and click on the necessary application to start using it. It is as simple as that.

The website provides the portable applications bundled as a suite in two different formats which is :

• Standard format 89.5 MB and
• Lite format 30.4 MB size
  

At present, there are over 50 different open source applications including the latest version of Firefox (2.0). And all the applications are guaranteed to work in Windows 98, Windows 2000, Windows XP, Vista and Wine. Some applications are also known to work in Windows 95 too.

Advantages of using portable apps
You can carry the following things with you on a USB stick ...

• Your web browser with all your favorite bookmarks
• Your calendar with all your appointments
• Email client with all your contacts and settings
• Instant messenger and your buddy list
• The whole office suite (OpenOffice.org) along with your documents and presentations
• An anti-virus program and other computer utilities
• All your important passwords and account information securely.
  

You can also put portable apps to use in diverse ways such as ...

• Have your favorite websites handy to recommend to a friend or colleague
• Have your presentation AND the required software ready to go for that big meeting
• Have your password with you if you want to bank online while traveling
• Have utilities handy when visiting family or friends that are having PC problems
  

If you are always on the move and are forced to use computers not your own, then this handy suite of open source applications will be a real convenience to you especially if you are wedded to using open source applications to get your job done.

How to create a custom DVD from multiple video formats

I have always found it a hassle to convert a video file from one format to another in Linux for lack of (or rather, not being aware of) a good Free video conversion suite. I have tried converting an Avi file to another format such as mp4 using some software but the results were far from satisfactory. I take it that it has more to do with the settings I selected than the fault of the software I used.

Axel has written a quite detailed article explaining how to create a custom DVD using a Free video conversion software called DeVeDe. What is really interesting about his article is that he shows the exact settings he used in the conversion - a big factor if you want your converted video file to have more or less the same quality. In fact my experience shows that you need to get the ratio of number of frames per second with respect to resolution of the video right else the quality of the video might suffer.

Fig: DeVeDe software interface

He has used the Windows version of DeVeDe but this is a software which is available for Linux as well. For example, in Ubuntu, you can install this software using the command :

$ sudo apt-get install devede

You need to have Mplayer, Mencoder, DVDAuthor, VCDImager, MKisofs and all the proprietary codecs installed though since DeVeDe is just a front-end. More over since DeVeDe is a Python script, it requires Python as well. For more details on the actual steps required to convert a video file from one format to another, do read the guide.

Google Talk - Instant messaging client for Linux

Roughly one year back, Google released its popular instant messaging application called Google talk which allows one to communicate with others, similar to the ever popular Yahoo Messenger. Initially Google talk client was available for Windows users only and people using other operating system such as Linux had to do with using the window which was embedded in their Gmail account. The problem was that to use Google talk, you had to log into your Gmail account.

Google has not yet released a native build of Google Talk for Linux. But what has changed is that it has now released a flash version of Google Talk which works in the same manner that an Instant messaging client is meant to work. The convenience for the Linux end user is that now in order to send text messaging using Google talk, one need not log into ones Gmail account but can directly access the Google talk interface as shown in the images below.

Fig: Google Talk web interface (Flash version)

Fig: Google talk - main view.

Fig: View once I have logged in.

Google Gears : Your Web applications can now be used even when not connected to Internet

Microsoft has had a definite advantage in being a virtual monopoly in the PC market. In the past few years Google has been trying to grab this enviable market share enjoyed by Microsoft by releasing web applications which have similar features of popular Microsoft software products. Thus you have Google spreadsheet as a potential replacement for MS Excel, Gmail, Google Docs as a replacement for MS Word and so on. But till now Google applications lacked a fundamental feature which was that none of the Google products could be used while you are offline. In other words, you needed an Internet connection to use any of the Google offering except Google Desktop search.

Now this is bound to change for once and all and you can look forward to Google storming one of the bastions of Microsoft which is the PC Desktop. Google has just released what they have named as Google Gears. Simply put, Google gears is a web browser extension which makes it possible to make web applications run while you are offline.

Google Gears provides three key features which are :

1. A local server, to cache and serve application resources (HTML, JavaScript, images, etc.) without needing to contact a server.
2. A database, to store and access data from within the browser.
3. A worker thread pool, to make web applications more responsive by performing expensive operations in the background.
   

Google has released Google Gears as a open source product which means, interested webmasters can use the API to develop their own web applications which work offline. You can go through a Google gears tutorial as well as access some sample applications to whet your appetite.

But what I find most enticing is the fact that Google has simultaneously released the web extension for Linux too along with that for Windows and Mac OSX. If you are interested in say, writing an email in your Gmail account while offline and then connecting to internet just to send the mail, then you can download and try out Google Gears.

LINA - Truly portable Linux applications

A truly portable application is one which can be run on multiple operating systems spanning diverse architectures without recompilation of code. One language which creates truly portable applications is Sun Microsystem's Java language. Programs created using Java can be run under any operating system - be it Mac OSX, Windows, Linux, OS/2 and so on. This is made possible because programs compiled using Java are not binaries in the original sense. When you compile a Java program, you get byte interpreted code. And it is the duty of the Java virtual machine which is installed in the parent OS to interpret the code to machine language which the OS and the architecture can understand.

Now there has been a new development for Linux. A startup company in Alameda, California has developed a technology called LINA (Not an acronym) which allows one to compile Linux applications to make them run in any operating system - be it Windows, Linux or Mac OSX. The idea is to have a virtual machine in similar lines of Java virtual machine which will be released as native builds for the respective operating systems. Then developers and independent software vendors can build Linux applications on top of LINA that run on all operating systems with native look and feel.

The company plans to dual license the technology, with GPL ver 2 for non-commercial uses and a separate license for commercial uses.

Salient features of LINA

• Applications written for LINA are distributed as Linux executables guaranteed to run on all machines, Linux and otherwise. So you can have say, one Firefox build which runs flawlessly in Windows, Linux, Mac OSX or any other operating system.
• Portable LINA applications enable users at home and in the enterprise to use Open Source applications on their existing operating systems.
• With LINA installed, programs written for Linux will run securely, regardless of changes made to the underlying operating system.
• Developers can write the code once and run their applications anywhere.
  

You can get an idea of running LINA applications by viewing this screencast which demonstrates how a Linux native build of links web browser packaged using LINA is run in Windows.The company has also released a white paper (PDF) describing the LINA technology. While some might see LINA as similar to what Sun Microsystems has accomplished with Java language, it is notably different. In the case of Java, it is required that programmers sit down and start developing programs using this language. But as far as LINA is concerned, the applications are already there in the form of 10s of 1000s of open source and Free Software programs for Linux. And it is only a matter of re-compiling the source of these programs to run using LINA virtual machine.

While many would consider this new project quite exiting (who wouldn't want a truly portable copy of their favorite Linux application, right?), there has been a somewhat similar project in existence for some time now which goes by the name Cooperative Linux. Short named as coLinux, it is a port of the Linux kernel that allows it to run cooperatively alongside another operating system on a single machine.

Work productively without starting X server in Linux

When was the last time you logged into a console only mode in Linux ? By console only mode I mean in run level 2 or 3 where X server is not running? Obviously now-a-days you needn't resort to such a drastic step as the GUI applications have gotten richer and the end user has a variety of choices before him. More over, most Linux distributions boot into graphical X by default the very first time they are installed. I am willing to bet that in a couple of years time, the new users embracing Linux won't have any idea of what a console mode is unless somebody specifically tell them.

This was not the same till a few years back (go back to 8 years) when even the average user had to first deal with the console mode and learn to start X by running a command before he was put into a graphical environment. He had to learn the syntax of the XF86config file (it is now xorg.conf), learn to use a console editor and so on before he was able to enjoy the fruits of Linux in GUI mode.

On this note, if you are wondering how the heck then the people using Linux were productive, it seems there were a number of command line tools at ones disposal. They are still around (if one bothers to look). Luke at "Terminally Incoherent" blog has compiled a nice list of command line tools in an article titled "A day without X", where he lists console programs that help one to accomplish common tasks like sending and receiving emails, web browsing, viewing images and so on. Another blogger, K.Mandala has also compiled his own list of command line applications which you can read here.

Who knows, if you face a situation where your favorite uncle gifts you with a 486 machine loaded with a stripped down version of Linux as a birthday present, you can genuinely be happy (instead of just pretending) and assure him that you will put it to good use....

Free Security Apps for Linux - a comprehensive list

When you hear the words "security apps", as an end user, one always tend to think of virus scanners, rootkit detectors, firewalls, network tools and so on. And Linux does not have a dearth of these tools which make it one of the most secure if not the most secure OS. Of course, how secure you can make your Linux machine will ultimately depend on your choice of Linux distribution and in what way you configure your machine. You can make your Linux box as open or as closed as you want.

ITSecurity - a website related to security has assembled a list of 103 free security apps. A large number of them are for Windows and Mac users but still, a significant percentage of them for Linux have also made it to the list. The applications have been categorized into 13 categories them being, Spyware, antivirus, rootkit, firewall, email, web utility, network, Intrusion detection system, Virtual private network, temporary files, wireless, encryption and a miscellaneous section.

You won't find Linux applications in all the categories. For example, the spyware category contain only Windows apps ;-). But this is a comprehensive list which lists many applications for Linux that I am aware of for the first time. I thought that ClamAV antivirus was the only antivirus solution for Linux but I was wrong, there are many more. Do check out the full list which will throw light on many applications and then some more which may be of use to all Linux enthusiasts.

Mount an Ext2 or Ext3 partition in Windows

There are different ways of sharing files between GNU/Linux and Windows. Mostly we make use of the services of a FAT32 (or FAT16) partition which can be read and written to by both Linux and Windows. The disadvantage of using a FAT partition for sharing files between Windows and GNU/Linux is that you are forced to reserve a part of disk space solely for sharing files. But this is just one of the number of file sharing methods available for people who wish to dual boot between the two OSes.

Another method which comes to my mind is to use the new stable release of ntfs-3g module which allows you to mount an NTFS partition as read-write in GNU/Linux.

But the method which has caught my fancy the most is a project which allows me to mount a ext2/ext3 GNU/Linux partition in Windows and assign it a drive letter similar to C:, D: and so on. The project in question is the Ext2fs installable file system. This project is the brain child of Stephan Schreiber. Once this driver is installed on Windows (98/2000/XP), you can easily mount a Linux partition on your computer into Windows and assign a drive letter to it. Once that is done, the files in the Linux partition can be browsed, read and written to.

Fig: Installing the Ext2 IFS driver

Fig: Another installation screen shot

The first step is to download the setup program from the ext2fs site and install the ext2 driver for Windows. Once the driver is installed, you will find an icon named "IFS Drives" in the Control Panel in Windows (See figure below). Double clicking on the icon will open a dialog box which will show all the partitions on your machine including the Linux partitions. Using the drop down box on the corresponding partition, you can assign drive letters to them.

Fig: Access the IFS GUI from the control panel in Windows

Fig: Assign drive letters to the ext2/ext3 partitions from the Ext2 IFS GUI.

Viola! now you can access the files on the corresponding Linux partition from the Windows file explorer by clicking on the drive letter you assigned to that partition. What is more, if you have a floppy which is formatted using the ext2 file system, then it could also be accessed in Windows without any problem.

Advantages of Ext2 IFS

• Read and write access to files residing in Linux ext2/3 file system from within Windows.
• Read and write access to floppies with ext2 file system.
• Seamless integration and use of ext2/3 file system in Windows to the extent that all applications have access to it.
  

Disadvantages of Ext2 IFS

• This program has a drawback in that it mounts only Ext2/Ext3 partitions. So if you have installed Linux on any other file system such as reiserfs, JFS or XFS then you are out of luck.
• Does not have support for Linux logical volumes. So if you use LVM in Linux, this software will be useless even if the underlying file system is ext2 or ext3.
• Current version of Ext2 IFS does not maintain access rights. So mounting an ext2 partition in Windows will give full access to the files on it to all the users.
  

While there are some limitations to this software as noted above, one convenience I see in using this method of sharing files between Windows and Linux is that once you have finished, you can also hide the corresponding Linux partition by re-opening the "IFS Drives" GUI front-end from the control panel and then removing the drive letter you assigned to the partition previously.

If by any chance you do not like any of the methods explained here, you can transfer files between Windows and Linux using a floppy or a USB key too ;-).