samedi 9 novembre 2013

PKI Implementation for the Linux Admin

http://www.linux.com/community/blogs/133-general-linux/742528-pki-implementation-for-the-linux-admin


Posted via Blogaway

Are Racks-on-Chip the Future of Data Centers?

UCSD News (CA) (11/04/13) Doug Ramsey 

Increasing the scale and decreasing the cost and power of data centers requires greatly boosting the density of computing, storage, and networking within those centers, according to University of California, San Diego researchers. The researchers say that one promising avenue to deliver increased density involves racks on a chip, or devices that would contain many individual computer processing cores integrated with sufficient network capability to fully utilize those cores by supporting massive amounts of data transfer into and out of them. However, to shrink data centers down to the size of a chip, a new data center network design is needed. "These integrated racks-on-chip will be networked, internally and externally, with both optical circuit switching [to support large flows of data] and electronic packet switching [to support high-priority data flows]," the researchers note. Each processor in the rack-on-chip design must have a transceiver, which converts the electrical signals in the processing core with the optical photons that travel through fiber-optic cables. "Once this optical networking technology is integrated with electronic processors as a rack-on-chip design, the number of such chips can then be scaled up to meet the needs of future data centers," the researchers report.

jeudi 7 novembre 2013

Richard Stallman's personal site.

http://stallman.org


How he do his computing

  • I use a Lemote machine which has a free initialization program and a free operating system. One other advantage of this machine is that Windows has never supported it.
    Before that, I used an OLPC for some weeks. I stopped because the OLPC project decided to make their machine support Windows, so I did not want to appear to endorse it. The OLPC uses a nonfree firmware blob for the WiFi, so I could not use the internal WiFi device. No big problem, I used an external one.
    The results I worried about, millions of children running Windows on the OLPC, have not occurred. Instead we see millions of children running Windows on the Intel Classmate.
    Before that I used machines that ran completely free GNU/Linux systems but had nonfree BIOSes. I tried for about 8 years to find a way to avoid the nonfree BIOS.
  • I do not have a preferred GNU/Linux distro. I recommend all the ethical distros — namely, those that are 100% free software.
    I've chosen not to have any preferences among those ethical distros. But I am not in a position to judge them on other criteria: even to try them all would be a lot work that I have no need to do.
  • I occasionally use X11 for tasks that need graphics, but mostly I use a text console. I find that the text console is more efficient and convenient for the bulk of the work I do, which is editing text.
  • I spend most of my time editing in Emacs. I read and send mail with Emacs using M-x rmail and C-x m. I have no experience with any other email client programs. In principle I would be glad to know about other free email clients, but learning about them is not a priority for me and I don't have time.

  • I edit the pages on this site with Emacs also, although volunteer helpers install the political notes and urgent notes. I have no experience with other ways of maintaining web sites. In principle I would be glad to know about other ways, but learning about them is not a priority for me and I don't have time.
  • This site is maintained in a very simple way. I edit the pages such as this one manually as HTML. I only know simple HTML; others who know more wrote the parts at the top and bottom of pages, and the more complex formatting on the home page. Volunteer helpers install the political notes every day after receiving the text from me by email. A cron job "rolls over" the political notes page every two months.
  • I never used Unix (not even for a minute) until after I decided to develop a free replacement for it (the GNU system). I chose that design to follow because it was portable and seemed fairly clean. I was never a fan of Unix; I had some criticisms of it too. But it was ok overall as a model.
  • Why I coined the name POSIX.
  • I have used the Internet since it first existed. I never used UUCP, though occasionally I sent emails to addresses that involved transmission via UUCP. However, I am careful in how I use the Internet.
  • I generally do not connect to web sites from my own machine, aside from a few sites I have some special relationship with. I fetch web pages from other sites by sending mail to a program (see git://git.gnu.org/womb/hacks.git) that fetches them, much like wget, and then mails them back to me. Then I look at them using a web browser, unless it is easy to see the text in the HTML page directly. I usually try lynx first, then a graphical browser if the page needs it.
    I also browse from other people's computers, with their permission. Since I don't identify myself to the sites I visit, this browsing can't be connected with me.
    One consequence of this method is that most of the survellance methods used on the Internet can't see me.
    Another consequence is that I never pay for anything on the Web. Anything on the net that requires payment, I don't do.
    I would not mind paying for a copy of an e-book or music recording on the Internet if I could do so anonymously, and it were ethical in other ways (no DRM or EULA). But that option almost never exists. I keep looking for ways to make it happen.

  • The most powerful programming language is Lisp. If you don't know Lisp (or its variant, Scheme), you don't know what it means for a programming language to be powerful and elegant. Once you learn Lisp, you will understand what is lacking in most other languages.
    When you start a Lisp system, it enters a read-eval-print loop. Most other languages have nothing comparable to `read', nothing comparable to `eval', and nothing comparable to `print'. What gaping deficiencies!
    Lisp is no harder to understand than other languages. So if you have never learned to program, and you want to start, start with Lisp. If you learn to edit with Emacs, you can learn Lisp by writing editing commands for Emacs. You can use the Introduction to Programming in Emacs Lisp to learn with: it is free as in freedom, and you can order printed copies from the FSF.
    Please don't buy books (or anything) from Amazon!
  • My favorite programming languages are Lisp and C. However, since around 1992 I have worked mainly on free software activism, which means I am too busy to do much programming. Around 2008 I stopped doing programming projects. As a result, I have not had time or occasion to learn newer languages such as Perl, Python, PHP or Ruby.
    I read a book about Java, and found it an elegant further development from C. But I have never used it. I did write some code in Java once, but the code was in C and Lisp (I simply happened to be in Java at the time).
    By contrast, I find C++ quite ugly.
    I skimmed documentation of Python after people told me it was fundamentally similar to Lisp. My conclusion is that that is not so. `read', `eval', and `print' are all missing in Python.
  • I firmly refuse to install non-free software or tolerate its installed presence on my computer or on computers set up for me.
    However, if I am visiting somewhere and the machines available nearby happen to contain non-free software, through no doing of mine, I don't refuse to touch them. I will use them briefly for tasks such as browsing. This limited usage doesn't give my assent to the software's license, or make me responsible its being present in the computer, or make me the possessor of a copy of it, so I don't see an ethical obligation to refrain from this. Of course, I explain to the local people why they should migrate the machines to free software, but I don't push them hard, because annoying them is not the way to convince them.
    Likewise, I don't need to worry about what software is in a kiosk, pay phone, or ATM that I am using. I hope their owners migrate them to free software, for their sake, but there's no need for me to refuse to touch them until then. (I do consider what those machines and their owners might do with my personal data, but that's a different issue, which would arise just the same even if they did use free software. My response to that issue is to minimize those activities which give them any data about me.)
    That reasoning is based on the fact that I was not responsible for setting up those machines, or for how that was done. By contrast, if I were to ask or lead someone to set up a computer for me to use, that would make me ethically responsible for its software load. In such a case I insist on free software, just as if the machine were mine.
    As for microwave ovens and other appliances, if updating software is not a normal part of use of the device, then it is not a computer. In that case, I think the user need not take cognizance of whether the device contains a processor and software, or is built some other way. However, if it has an "update firmware" button, that means installing software is a normal part of use, so it is a computer.
    Skype (or any nonfree noninteroperable communication program) is a special case. Using Skype to talk with someone else who is using Skype is encouraging the other to use nonfree software. So I won't use it under any circumstances.
    Streaming media dis-services such as Netflix and Spotify are another special case. They require nonfree client programs in order to impose Digital Restrictions Management (DRM ). We should never use DRM that we can't break, and I don't know how to break the DRM of these streaming systems, so I refuse to use them under any circumstances.
  • I sometimes use Google's search engine, and I sometimes use DuckDuckGo. When I use a search engine, it is always from a machine that isn't mine and that other people also use. I never identify myself to the site, of course.
  • I do not use social networking sites. They are inherently inconvenient for me. That doesn't mean I think they are all unethical. Some are, some are not. Social networking sites raise their own set of ethical issues, completely different from the ethical issues of distributing software (free vs proprietary).
    I have a Twitter account called rmspostcomments, which I use to log in on other sites to post comments on articles. I never post on Twitter. Someone made an account stallman_feed which I'm told posts something about my political notes. Any other Twitter account that claims to be mine is an impostor.
    The rms account on identi.ca repeats the political notes from this site, but I do not post on it directly.
    Aside from those two, any account on a social networking site that says it is mine is an impostor.
    I do not post on 4chan. I have nothing against it, and I have occasionally answered questions for interviews for 4chan, but any account there that says it is me is an impostor.
    I reject Facebook and Google+ on principle because they require people to give their "real names". I am proud to identify myself when stating my views; I can afford to do that because I am in a fairly safe position. There are people who rationally fear reprisals (from employers, gangsters, bullies, or the state) if they state their views. For their sake, let's reject any social networking site which insists on being told a user's real name.

    Google+ offers to hide the user's real name, but demands people prove an "established identity" or provide ID. I am suspicious of this requirement, since it can't hide the user's real name from the US government, which has a policy of prosecuting journalists as "spies".
    Of course, Facebook is bad for many other reasons as well. Google+ also has another problem: the site requires running nonfree JavaScript code in order to post a message.
    Some impostor created a Faceook account using my name. The page is not mine. The Google+ account using my name is also not mine.
  • People sometimes ask me to recommend an email service. The two ethical issues for an email service are (1) whether you can use it without running any nonfree software (including nonfree Javascript code from the site), and (2) whether it respects your privacy.
    For issue 1, see the FSF's page. On issue 2, I have no way to verify that any email service is satisfactory. Therefore, I have no recommendation to offer.
    However, I can suggest that it may be wise to use an email service that is not connected with your search engine. That way you can be almost sure that your email contents don't influence your search results. You shouldn't identify yourself to your search engine in any case.

  • Every product with Digital Restrictions Management (DRM) is an attack on your freedom.
    Therefore, one should not buy or tolerate any product with DRM handcuffs unless one personally possesses the means to break the handcuffs. For instance, don't use encrypted DVDs unless you have DeCSS or another comparable free program. And never use a Bluray disk unless you find a way to break its handcuffs. Don't use the Amazon Swindle or other e-book readers that trample readers' freedoms. Don't use music or video streaming "services" that impose DRM. (If they require a nonfree client program, it is probably for DRM or some sort of surveillance of users.)


Return to Richard Stallman's home page.

mardi 3 septembre 2013

Linux today

3 Secrets for Exceptional Web Application Performance
Download this article to learn the 3 secrets to assure predictable web application performance, and why a new approach can help your organization deliver exceptional application service and end-user experience. Click Here >>

GNOME Web To Abandon Google Search
Phoronix: The GNOME Web Browser will no longer be using Google as its default search engine but they have struck a deal to use DuckDuckGo as its new search engine. Read more >>
5 Things to Know About Salt Cloud Management
Linux.com: You will be forgiven if you haven't heard of the Salt project. Read more >>
22 Years Later, The Linux And Open Source "Cancer" Is Wonderfully Benign
readwrite: Linux just turned 22 and the open source revolution it sparked is just getting started, two experts suggest Read more >>
Kevin Mitnick Details Modern IT Threats
eWEEK: video: One of the most infamous hackers of all time talks about Website security and what users should do to protect themselves. Read more >>
Will Firefox OS beat Ubuntu in smartphone sales?
ITworld: I can't say I'm surprised the first shipment of Firefox phones sold out. Read more >>

+Pascal Fares 

"Linux LPIC 101 – Free 15-Minute Guide"

Free Guide to Linux LPIC 101 – Free 15-Minute Guide. PrepLogic's LPIC1 Exam 101 Mega Guide vividly details the topics and domains you're expected to know for your 

lundi 2 septembre 2013

Configuring Apache 2 on Debian, Ubuntu

The Debian distribution of Linux includes the Apache web server, both the venerable version 1 and the more modern version 2. The Debian maintainers have a peculiar way of arranging the configuration files for Apache 2.0 which is not documented in the standard Apache documentation. This introduction should help you get acclimated to the Debian way of configuring Apache 2.0.

Active Configuration Files

# /etc/apache2/apache2.conf - pulls in additional
# configurations in this order:
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf
Include /etc/apache2/httpd.conf
Include /etc/apache2/ports.conf
Include /etc/apache2/conf.d/[^.#]*
Include /etc/apache2/sites-enabled/[^.#]*
Debian stores its Apache 2.0 configuration files in the directory /etc/apache2. Normally the main Apache configuration file is called httpd.conf. Although that file exists on Debian, it is only there for compatibility with other software that expects it to exist. The real configuration starts with the file apache2.conf. You can still add configuration statements to httpd.conf, as apache2.conf includes it, but you would do well to ignore that fact. Your hand-edited changes should go elsewhere (see below).
Debian adds another configuration file, ports.conf, which contains the Listendirectives telling the Apache server what IP address and port to listen to (Apache 2 no longer uses the Port directive.) I’m not sure why the maintainers decided to break this out into a separate file.
The best place to put your own custom configurations is in the conf.d directory. Files in this directory are included as part of the “global” server configuration and will apply to all virtual hosts (see below). For example, if all the sites on your server use the Yahoo User Interface libraries, you might store one copy of the libraries in a central location that can be shared across all sites, and create a file /etc/apache2/conf.d/yui.conf with an Alias directive to map it to the same URL space for all sites.

Apache Modules

# Files related to Apache modules
/etc/apache2/mods-enabled/*.load
/etc/apache2/mods-enabled/*.conf
/etc/apache2/mods-available/*.load
/etc/apache2/mods-available/*.conf
/usr/sbin/a2enmod
/usr/sbin/a2dismod
One of the great advantages of the Apache web server is its modular architecture. You can add or remove functionality as dictated by your requirements. In the default Apache build, you would find a section near the top of your httpd.conf file with instructions to load each module. Later in the file, you would find configuration sections specific to each module, possibly wrapped in a<IfModule> directive. This arrangement can be tricky from the perspective of a system administrator who may need to install or uninstall various Apache modules. Identifying the configuration changes that are required by a module or that require a specific module can be difficult to do by hand and even harder to automate with a script.
To make things easier on the server administrator, Debian takes advantage of the fact that Apache configuration files may contain an Include directive which pulls in additional configuration files. Debian creates two non-standard directories: /etc/apache2/mods-enabled and /etc/apache2/mods-available. Whenever you install an Apache module from a Debian package, the module will drop one or two files into the mods-available directory. The mandatory ${module}.loadcontains the Apache Load directive to load the module into your web server. The optional ${module}.conf file contains additional configuration directives necessary for the operation of the module.
Installing a module from a Debian package makes it available to your server, but does not (necessarily) automatically activate the module in your server. To activate the module, use the a2enmod command:
a2enmod ${module}
/etc/init.d/apache2 force-reload
The a2enmod command will create symbolic links in the mods-enabled directory pointing to your ${module}.load and, if it exists, ${module}.conf. To force a running Apache to re-read its configuration files and thus load the module, you must then send it the force-reload signal.
Likewise, to disable a module:
a2dismod ${module}
/etc/init.d/apache2 force-reload
Issue either command without a module argument and it will print a list of appropriate module names.
You can, of course, manually manage the symbolic links in the mods-enableddirectory, but it is safer and easier to use the provided scripts.

Virtual Hosts

# Files related to Apache virtual hosts
/etc/apache2/sites-enabled/[^.#]*
/etc/apache2/sites-available/*
/usr/sbin/a2ensite
/usr/sbin/a2dissite
Virtual Host is just a web site served by your Apache server. Virtual hosts are managed just like modules. Each site gets its own configuration file that contains all the Apache directives that pertain only to that site. These files (or symbolic links to them) should be placed in the sites-available directory. There are no strict naming requirements for these files (files beginning with . or # will be ignored), but for convenience you should name each site configuration file to match the domain name it is serving. There is no need to add a “conf” extension. For example, the vhost file used for this web site is namedwww.control-escape.com.
To activate any of these sites, use the a2ensite command, which operates identically to the a2enmod command mentioned above. There is a respectivea2dissite command for disabling a site.
Even if you only run one web site on your server, Apache is still configured to have one virtual host, the Default Virtual Host. The default virtual host is treated specially by the a2ensite script. If you look in your sites-enabled directory you will find that the link has been named 000-default. The number is prepended to the name by the a2ensite script to ensure that the default virtual host is the first one included by Apache (which sorts the files alphabetically). If you want other sites to be loaded in a particular order other than alphabetical, you can rename the links here, but you should always ensure that the default virtual host is the first one loaded.

Conclusion and Resources

Although Debian’s configuration setup for Apache 2 is non-standard, it is still fairly easy to understand, and it provides tools that make life easier for the administrators of web servers that change often or serve multiple web sites. For additional help, view the Debian README file at /etc/apache2/README. For general information on configuring Apache, try these resources.
To learn more about Debian GNU/Linux, visit Debian.org.
To learn more about Ubuntu, visit Ubuntu.com, or buy a copy of The Official Ubuntu Book

lundi 26 août 2013

Today, in 1991, Linus Torvalds sent that 'famous' email




Posted: 25 Aug 2013 07:44 PM PDT
It was August 25, 1991 when some Linus Benedict Torvalds sent an email introducing the world to some 'tiny' project he was working on.

Posted: 25 Aug 2013 03:27 PM PDT
Google has pushed an update for ChromeCast which has broken support for 3rd party apps like AirCast (AllCast) which allow users to 'stream' local files from their devices to ChromeCast connected TV sets.