Practical Technology

for practical people.

October 28, 2010
by sjvn01
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China has the top supercomputer in the world but it still runs Linux

If you want a really, really fast computer, there are all kind of ways to build the hardware architecture, but one thing that almost all of them have in common is that they run Linux. The top spot now appears to belong to the Tianhe-1A , which means "Milky Way," at a research center at the National University of Defense Technology (NUDT) in Tianjin, China.

I say "appears" because the official Top 500 Supercomputer List won’t be out until early November. Still, according to a New York Times report, Jack Dongarra, the University of Tennessee computer scientist who maintains the Top 500 ranking, said, the Tianhe-1A "blows away the existing No. 1 machine," which is a Cray XT5 Jaguar at the National Center for Computational Sciences. Dongarra concluded, "We don’t close the books until Nov. 1, but I would say it is unlikely we will see a system that is faster."

How much faster? NUDT claims the machine is 1.4 times faster than Cray XT5 Jaguar. NUDT claims that the computer’s peak performance can hit 1.206 petaflops and jogs along at 563.1 teraflops. To do this, the Tianhe-1A system covers a square kilometer, weights in at 155-tons and uses 14,336 Intel Xeon CPUs and 7,168 Nvidia Tesla GPUs.

The software behind it? Linux of course. Linux has long been the operating system of choice for the world’s fastest computers. While NUDT hasn’t said which specific Linux they used, I strongly suspect it’s a high-speed optimized version of China’s Red Flag Software’s Red Flag Linux.

It’s not just supercomputers that have become Linux fans. Other high-speed, no-room-for-failure systems have moved to Linux. The one that comes first to my mind is the London Stock Exchange, which dumped its slow Windows/.NET system for Linux. It’s not the only one. Many of the world’s stock exchanges, where every millisecond counts, have either already switched to Linux or are planning on it.

The bottom line: when speed and reliability is what you have to have, Linux is the operating system you have to use.

A version of this story was first published in ComputerWorld.

October 26, 2010
by sjvn01
0 comments

What’s really going on with Ubuntu Unity

ORLANDO, FLA.–As Debian is to Ubuntu, so GNOME is to Unity. What do I mean by that? Well, once upon a time there was an operating system called Debian. It was, and is, a powerful version of Linux. Outside of the Linux community, though, almost no one had ever heard of it. Then Ubuntu came along, built its own easy-to-use distribution on top of Debian, and now it’s arguably the most popular Linux in the world.

Yesterday, Mark Shuttleworth, founder of Canonical, the company behind Ubuntu, announced at the Ubuntu Developer Summit that Ubuntu was switching its default desktop from GNOME to Unity, a GNOME-based shell interface. Guess what he hopes will happen?

If you answered, create a desktop interface that will bring millions more desktop users to Ubuntu, congratulations, you win a prize. Unity is not just a desktop interface though. It’s also Ubuntu’s one master interface for desktops, netbooks, and someday, tablets.

While a tablet version of Ubuntu isn’t in Canonical’s immediate plans, Jono Bacon, the Ubuntu Community Manager, told me that "all the pieces are in place to create an Ubuntu tablet."

He’s right. Later that same day, Canonical multi-touch and kernel developer Chase Douglas showed me the first baby steps of multi-touch Unity on a 22-inch 3M Multi-touch Display M2256PW. I was impressed.

I’ve seen lots of touch systems. Most of them have left me unmoved. This, though, was the first PC touch system I could actually see taking off in the mass market. What’s more important than what I think, though, is that the software toolkit developers and vendors are interested in it too. That means that multi-touch applications may be ready in time for the Unity-based Ubuntu launch in April.

I shouldn’t have been surprised. If you take a look at Unity, you’ll see a desktop interface that clearly meant for touch.

You can also dismiss the silly idea that Unity is some kind of fork from GNOME. It’s not. As Shuttleworth said, "Unity is a shell for GNOME, even if it isn’t GNOME Shell. We’re committed to the principles and values of GNOME."

The next question people ask is: "Why didn’t Ubuntu work with GNOME on this?" The answer is that these two group of developers have fundamentally different views of what they wanted from the shell, the first interface that users will encounter. For example, GNOME’s didn’t want global menus, while Ubuntu really wanted them.

Under the hood, there were also technical differences. Ubuntu’s developers greatly preferred using Compiz for the windows manager over GNOME’s Mutter windows manager. Ubuntu developers also like Zeitgeist, a framework that tracks and correlates relationships between the user’s activities so that it can supply applications with contextually relevant data.

Although many Unity users like it even now, Unity still has a long way to go. Penelope Stowe, co-leader of the Ubuntu accessibility team, said she was concerned that there was "very little time to do some very important work on making sure that Unity is accessible to all users." That’s an excellent point.

I’m seeing great potential here. Now, we need to see the reality, and that will be at least six months away.

Still, while Unity has a long way to go, I see Unity as becoming very popular with users who might never have considered Linux before. Even in this early form, it’s simple to use. Unlike any other operating system interface, it can also be used from desktops to netbooks to tablets. I think many users are going to find a system that will look and act the same no matter what device they’re using to be very attractive.

Don’t like it? Don’t worry about it. Ubuntu will have the full GNOME desktop a click or two away. Don’t be surprised, though, if many users, especially ones who are new to Linux, find Unity to be just the desktop they’ve been looking for.

A version of this story first appeared in ComputerWorld.

October 25, 2010
by sjvn01
0 comments

Wi-Fi Direct: Really fast but Really Necessary?

is one of those technologies that sounds like it makes sense, but then if you really think about using it in real life…. well then it doesn’t sound so great.

The idea is simple. There are two ways you can do Wi-Fi. There’s infrastructure, where you have an access point and a lot of clients and then there’s ad hoc, where laptops share network with one another in peer-to-peer mode. Ad hoc, as anyone who uses it knows, has awful throughput but the security is even worse. With Wi-Fi Direct, you get peer-to-peer Wi-Fi connections between devices like camera and a printer without an existing network.

That could be useful for grandma who just wants to get the photos of the new grandkids from her PC to her digital picture frame, except… well how does she do that again? The technology may make this possible, but I don’t see much in the way of the all-important implementation details worked out yet.

For everyone else, we already have our Wi-Fi networks right? Do we really need what amounts to a long range, high-speed rival to Bluetooth? I don’t think so.

Under the hood Wi-Fi Direct uses the same old Wi-Fi wireless technologies. According to the Wi-Fi Alliance, Wi-Fi Direct will work with 802.11a/b/g/n networks and it all be as easy as pie.

Except, of course, it won’t be that easy.

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October 25, 2010
by sjvn01
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Ubuntu changes its desktop from GNOME to Unity

ORLANDO, FLA. — Mark Shuttleworth, founder of Ubuntu and the company behind it, Canonical, surprised the hundreds of Ubuntu programmers at the Ubuntu Developers Summit when he announced that the next release of the popular Linux operating system, Ubuntu 11.04, would use Unity as the default desktop interface because "users want Unity as their primary desktop."

Unity is Ubuntu’s new netbook interface that, while based on GNOME, is its own take on what an interface should look and act like. To make it work on the desktop instead of on the netbook, where one foreground activity at a time is the rule, Shuttleworth admitted that Ubuntu had "A lot of work to do around windows management." That said, "We are committing to the biggest change on the desktop. Unity will become the default, when we’re sure that it will work."

Shuttleworth hopes — expects, really — that this switchover will be completed by the next release. "Lots of people are already committed to Unity — the community, desktop users, developers, and platform and hardware vendors." In particular, he noted, original equipment manufacturers (OEMs) favor Unity. They’re happy to ship it.

In an interview after the presentation, Shuttleworth added that Dell, which he said had sold several million Ubuntu desktops, laptops, and netbooks, supports the project. In addition, Canonical has overarching deals in place with Lenovo and Acer. These arrangements may lead to these major PC OEMs releasing Ubuntu desktops as well.

One reason Shuttleworth cited for this switch is that that using one interface for both netbooks and desktops will improve quality assurance and make it easier for OEMs to integrate and support Ubuntu across their PC platforms. In short, "There will be no fault-line for OEMs between desktops."

For users, the new Ubuntu Unity will default to either a single window for a single foreground application on netbooks, or to multiple windows for a multi-foreground interface on a desktop or laptop. Of course, users can choose whichever of these environments they wish, or use the GNOME desktop or the closest thing GNOME has to Unity, the GNOME Shell.

During the announcement, Shuttleworth said that this "is a significant, risky step. It will throw people’s confidence. I will preempt one important question: Unity is a shell for GNOME, even if it isn’t GNOME Shell. We’re committed to the principles and values of GNOME." Afterwards, Shuttleworth told me he would be speaking to Stormy Peters, executive director of GNOME, to further explain Ubuntu’s position directly to the GNOME community.

Shuttleworth also said that touch, which was introduced to Ubuntu in the most recent version as Utouch, will be integrated into Unity and applications. "I think in the near future all laptops will have sophisticated multi-touch hardware. All the hardware vendors that are working on touch are talking to Ubuntu."

Not everyone is happy about Ubuntu’s desktop shift. Some see this move as creating yet another division in Linux circles. Shuttleworth admitted that "There is a group that will take offense," but he thinks if Linux users and developers focus more on what they have in common rather than their differences, this move will be good for Linux, GNOME and Ubuntu.

A version of this story first appeared in ComputerWorld.>

October 22, 2010
by sjvn01
0 comments

The Internet belongs to Netflix

If I were to ask most people what single kind of program they thought used up the most Internet bandwidth, most of them would say, “Web browsing.” Wrong. According to research by Sandvine, a broadband solution provider and analysis firm, the Web takes up only 24.3%. Someone who pays attention to the net might guess peer-to-peer (P2P) file sharing such as BitTorrent. Nope. P2P has actually declined in recent years. In 2010, it only takes up 13.2%. The winner, by a wide margin, is Real-Time Entertainment, aka video and music-streaming, which accounts for 45.7% of data. Number one with a bullet in this category is Netflix.

Netflix!? Yes, Netflix. To be exact, according to Sandvine, “20.6% of all peak period bytes downloaded on fixed access networks in North America are Netflix.” That’s one in five bytes devoted to streaming Star Trek or The Girl with the Dragon Tattoo. Who knew?

You may think of Netflix as that mail-order DVD business, but the company’s growth as an Internet video-on-demand (VoD) service has been explosive. Now, if only the Internet can keep up with the demand.

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October 21, 2010
by sjvn01
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Practice Safe DNS

Misery is when you head to one of your usual Web site hangouts and find yourself somewhere nasty instead because of Domain Name System (DNS) poisoning. DNS cache poisoning doesn’t happen often, but when it does happen, it can make large parts of the Internet unusable. The answer to this potential poison problem? Domain Name System Security Extensions (DNSSEC).

DNS poisoning works like this. The DNS is the master address list for the Internet. With it, instead of writing out an IPv4 address like “http://209.85.135.99/,” one of Google’s many addresses, you can simply type in “http://www.google.com” and you’ll be you on your way. But, how can your browser be sure that “209.85.135.99? is a correct address for Google? By itself, it can’t. It relies on DNS and, here’s the kicker, with plain Jane DNS, the system doesn’t have any built-in way to make sure that the information it’s feeding your browser is the real deal.

DNSSEC attempts to prevent DNS cache poisoning attacks by requiring Web sites to verify their domain names and corresponding IP addresses with DNS servers. To make sure this information isn’t compromised DNSSEC uses digital signatures and public-key encryption for this information exchange. That, in turn, makes it much harder for a cracker to effectively attack a DNS server since for an attack to work it needs to compromise the DNS information for popular Web sites.

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