Authors: Remo Suppi Boldrito, Josep Jorba Esteve
Coordinator: Josep Jorba Esteve
Licenses: GNU Free Documentation License, Creative Commons Attribute ShareAlike License

The GNU/Linux systems have reached an important level of maturity, allowing to integrate them in almost any kind of work environment, from a desktop PC to the sever facilities of a big company.

In the module called "The GNU/Linux operating system", the main contents are related with system administration. This book is the main documentation for the module.

We will learn how to install and configure several computer services, and how to optimize and synchronize the resources.

The activities that will take place in this module cover the studied topics in a practical approach, applying these concepts in real GNU/Linux systems.

Version 3.1.0 is a major update with the following major new features:

• Teleportation (aka live migration); migrate a live VM session from one host to another
• VM states can now be restored from arbitrary snapshots instead of only the last one, and new snapshots can be taken from other snapshots as well ("branched snapshots")
• 2D video acceleration for Windows guests; use the host video hardware for overlay stretching and color conversion
• More flexible storage attachments: CD/DVD drives can be attached to an arbitrary IDE controller, and there can be more than one such drive
• The network attachment type can be changed while a VM is running
• Complete rewrite of experimental USB support for OpenSolaris hosts making use of the latest USB enhancements in Solaris Nevada 124 and higher
• Significant performance improvements for PAE and AMD64 guests (VT-x and AMD-V only; normal (non-nested) paging)
• Experimental support for EFI (Extensible Firmware Interface)
• Support for paravirtualized network adapters (virtio-net)

Current default for X servers as shipped in various distributions is to not enable the traditional Ctrl-Alt-Backspace key combination to kill the X server. If you would like to re-enable this feature, you may do so in your desktop's Keyboard Preferences application. You may also enable it for the current session using the command "setxkbmap -option terminate:ctrl_alt_bksp".

Over the years I have had to harden a great number of LAMP boxes, I have found some methods work for better than others. I will now share with you all my favorite 10 along with methods to implement them on Debian/Ubuntu.

10. Lock SSH access right down. I do this by disabling root logins, disabling password authentication and using denyhosts.

To disable root logins do this: vi /etc/ssh/sshd_config and look for the following line: PermitRootLogin yes and change it thus: PermitRootLogin no

To disable password authentication (you will have to use public/private keys) do this: vi /etc/ssh/sshd_config and look for the following line: #PasswordAuthentication yes (note its commented out) and change it thus: PasswordAuthentication no

To install denyhosts do this: apt-get install denyhosts once installed it shouldn't need any configuration, but you can tweak the settings if you wish in /etc/denyhosts.conf

9. Always use Sudo for root access, This is one of the things Ubuntu does really well and its about time other distros did the same.

No comment. :)

Eclipse + EPIC, Perl Express, Padre, Kephra, Open Perl IDE, Perl Code Editor, Perl Studio, visiPerl+, Perl Scripting Tool, EngInSite-Perl, PerlEdit, PerlWiz, DzSoft Perl, OptiPerl, Perl Builder, SciTE, Notepad++, NEdit, Vim (or vi or gvim), Kate, FTE, Emacs (or xemacs, with or without extensions), KDevelop, Joe, Jed, Gedit, Anjuta, JEdit, Komodo IDE, Komodo Edit, Prof. Notepad, Ultra Edit (plain or Studio), EditPlus, ED for Windows, TextPad, Editeur, TextMate, Notepad2, Pico, Geany, nano, PSPad, Smultron, SlickEdit, mcedit, BBEdit, TextWrangler, KEdit or something else?

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Appeared as a full page advertisement in the Wall Street Journal. You have to admit Larry Ellison that he has a sense of humor. Anyway, I'm glad that Oracle will continue work on improving Sun technologies, both hardware (SPARC) and software (Solaris). But it remains to be seen what happens with other products that Sun acquired (before Oracle bought Sun) that are not mentioned explicitly in the ad. Stuff like MySQL database, VirtualBox virtualization and so on...

Mark Jason Dominus' absolutely great Perl book is now available for free download in PDF format by virtue of special permission from the publisher.

Higher-Order Perl is about functional programming techniques in Perl. It's about how to write functions that can modify and manufacture other functions. Why would you want to do that? Because that way your code is more flexible and more reusable. Instead of writing ten similar functions, you write a general pattern or framework that can generate the functions you want; then you generate just the functions you need according to the pattern. The program doesn't need to know in advance which functions are necessary; it can generate them as needed. Instead of writing the complete program yourself, you get the computer to write it for you.

Preface by Damian Conway, Co-designer of Perl 6

As a programmer, your bookshelf is probably overflowing with books that did nothing to change the way you program... or think about programming.

You're going to need a completely different shelf for this book.

While discussing caching techniques in Chapter 3, Mark Jason Dominus points out how a large enough increase in power can change the fundamental way you think about a technology. And that's precisely what this entire book does for Perl.

0 A.D. is a free, real-time strategy game currently under development by Wildfire Games. It's cross-platform, 3D and historically-based. Wildfire Games is switching from a closed development process to open source, making the game's code available as GPL and the art content available as CC-BY-SA. People are encouraged to reuse and learn from and improve their work. They are not releasing a playable game, but want to show what they have achieved and make it easier for more people to get involved in bringing it closer to completion.

There's roughly 150K lines of C++ for the game engine, and another 25K for editing tools. Gameplay scripting uses JavaScript. The game is built on top of low-level libraries (OpenGL, OpenAL, ENet, ...), not an existing game engine (like OGRE).

They admit the code isn't all extremely clean or extremely modular or extremely well-written. It's been written by a wide variety of programmers, and it's far from a "completed" code base. They want to continue cleaning things up as part of the normal development process. They're not averse to rewriting entire subsystems if that's the most effective way. But in many areas it's quite solid.

Most of the code is specific to the game and not very useful outside it, but some parts could perhaps be interesting for developers working on other projects. Some examples:

• Low-level library providing cross-platform support for resource management (archive file loading, GL textures and shaders, ...), debugging tools (error reporting, memory tracking, stack dumps), timers, asynchronous IO, allocators, ...
• Converter from COLLADA models with skeletal animation into a simple game-friendly format.
• Binary XML caching system, for faster resource loading.
• Automated build tools using Amazon EC2.
• Boring maths code for matrices, vectors, quaternions, etc.

Check out their open source page for more details and info on how you can contribute.

With the attached patch you can persuade your VMware Workstation to work on the newest Linux kernel 2.6.29. There are no guarantees, but it works for me(tm).

Unpack tar's from /usr/lib/vmware/modules/source into some directory (except vmppuser.tar), patch the source (patch -p1), run make in every subdirectory, copy resulting kernel modules to /lib/modules/2.6.29/misc and run depmod -a. Then you can run /etc/init.d/vmware start and check that all modules loaded correctly. That should be it.