Linux Community Magazine

DNS is the Domain Name System, an internet task force that allows the computer to register to domain names, or as we mostly know them online resources. Once you type the address of a website and actually visit it, your computer will store the DNS information this happens only the first time that you visit every website. All the subsequent times that you will visit the particular website, the computer will search for the so called DNS cache, which defines the information stored from the previous time. Once the information is located, the computer is ready to use it, instead of registering all over again. This allows the exchange of DNS information to be faster and the DNS resolution easier.

Every address is stored for a day 24 hours. If the IP of the particular website changes for any reason within these 24 hours, then the DNS cache will give you an error message and will inform you that it cannot connect you to the website you want.

Even the slightest change in the stored information can cause some issues. This is where flushing DNS comes to the game. Although few users know how to flush DNS, it is an action of significant importance, because it can resolve cache and help it locate the pertinent DNS information for the particular website. The DNS cache cannot recognise problematic entries and can store everything, causing malfunctions later on; this can prohibit your connection to the website you want. Knowing how to flush DNS can help you restore the positive information and help your computer connect to any page.

How to Flush DNS if you have Windows XP or Vista?

The first thing you need to do is to use the ipconfig /flushdns command. Type C:>ipconfig /flushdns and you will manage to configure IP and flush the Resolver Cache.

What can you do if you have a Mac?

If your operating system is Mac OSX Leopard, you can type the command bash-2.05a$ dnscacheutil -flushcache

If your operating system is OSX and older, then you can perform this task typing bash-2.05a$ lookupd -flushcache

If you are working on Linux, then you can use the nscd demon to manage the problem: you need to restart the demon, using the command `/etc/init.d/nscd restart`.

Is Linux the best way to go?

Nicely that's a question that doesn't have an easy answer. Some people, principally hardcore gurus, will say "Yes it positive is!" but believe it or not there are individuals who nonetheless like Windows.

With regards to deciding between installing Linux as a substitute of Home windows (or any other working system) you could keep various things in mind. Below is an inventory of the five key things you'll want to think about before choosing.

1. Is that this going to be used as a desktop or server system? - Linux has been primarily used within the mainstream server world as internet and ftp servers. There are lots of types of servers that you may run with Linux akin to DHCP (BOOTP in Linux phrases), listing companies (LDAP), and plenty of more.

2. What software program is going to run on this pc? - There are many purposes that still haven't been written for Linux. Test along with your software program vendor before installing Linux to see if they have a model of their software program that can work.

3. Are you going to be playing video games? - As with different software program, there are lots of video games that haven't be ported over to Linux. In case you are really right into a certain game and it doesn't exist in a Linux version you would possibly need to contemplate staying with Windows.

4. What is your degree of laptop data? - Since Linux is completely completely different than Windows you'll probably have to learn every little thing from scratch. Issues equivalent to installing software, booting up, and deleting files are fully different. In case you are not willing to take some time to be taught a new operating system then you could want to steer clear.

5. What's the price? - Well with Linux there are price ranges, free and never so free. The principle thought behind Linux is the "Open Source" concept. This mainly implies that the code of the working system is free to use, distribute, and modify at your will. This is good as a result of most Linux distributions are free. It also implies that corporations can package and promote it below their own name. Ordinarily if you wish to go with Linux you must persist with the free versions.

After you have got considered these 5 questions it is best to have a good idea of whether or to not install Linux on your computer. The main advantage of Linux is that there are tons of free variations out there. Over the past few years Linux, on the whole, has grown quite effectively and there are lots of resources, on the internet, where yow will discover info, explanations, and tutorials on just about anything to do with it.

While the Palm has always been the top dog of palmtops for Linux users and Yopy (see "Linley on Linux", LJ, September 2000) is the first kid on the block with Linux inside, there is Linux brewing at Compaq as well. iPaq, the handheld pocket PC from Compaq, should have the attention of most Linux lovers. While the shipping version runs Windows Pocket PC, getting a Linux version of this 200MHz handheld with 32MB of flash RAM is as easy as surfing to the Compaq web site. And what's more, the iPaq owes its very existence to open source and Linux in general, and a research project called "Itsy" in specific.

As Dick Greeley, program manager for the Open Handheld program and a member of Compaq's Corporate Research team, said in a recent interview, Compaq's study of handheld computing devices-seeing what it was that made them so popular and what could be done to improve on some of the product's deficiencies-had it origins not in Compaq, but in Digital Equipment Corporation, which Compaq acquired in 1998. Getting Digital's significant research labs as part of the bargain, Compaq became the home for Digital's "Itsy" project. The "Itsy" project was an attempt to marshal many of the technological innovations in computing power, screen quality and memory capacity for the burgeoning handheld computer market. It is this project, started four years ago, that eventually produced the iPaq.

"Our goal in research," said Dick Greeley, "is to look into the future, to look beyond the time horizon of the existing business units, so to that extent, we're looking out further than a lot of these groups do." What he and his researchers saw was that issues of power management and user interface were key to developing handhelds that would be popular and able to exploit the developments that were leading to the incredible shrinking machine. "While all these devices could shrink," Greeley noted, "our fingers can't, our eyes and ears can't...so we needed to start thinking about how the user interface of the future is going to work with these devices...what can and can't be done and how will people really want to relate to them."

Building a better user interface for handhelds led the Itsy team to a number of interesting innovations, one of which was the addition of a 3-D accelerometer which enabled a user to measure when the Itsy unit was tilted or moved. What good was this? Greeley calls it a "rock and scroll" interface. "The idea is that as you flip the unit around in your hand, it would be basically programmable and would do different things for you," he explained, using the example of being able to turn pages on a particular application simply by flipping the wrist. So giddy had the Itsy team become with the success of their early prototype device-which was about the size of a deck of playing cards-that they even loaded the popular action-shooter game, DOOM, onto it. Recalled Greeley, "I think my favorite aspect was how you cocked the shotgun, by flipping the unit forward and backward."

Why did the Itsy team choose Linux as the development operating system? Dick Greeley offers a number of reasons. For one, like many developers, they wanted something they could play with-from the source-code level up-on their own, without any proprietary strings attached. Second, the fact of the matter was that the Itsy project was not a secret; numerous developers from the academic and research communities were also involved to one degree or another. This involvement also led to the founding of the Compaq Laptop Battery web site and the Open Handhelds program, which has as its goal the continued support of Linux on the iPaq, making the device available to the research/development community.

While the Itsy team choose Linux as their operating system, Greeley admits that, within Compaq, his research team is pretty "operating system agnostic". He adds, "I think what's more critical than necessarily the OS choice is the notion of going open source, to be able to share and interchange the fruits of many people's efforts and to have access to a wide variety of applications that are out there, which makes innovation really possible."

The transition from Itsy to iPaq took place when the newly Compaq'd Itsy research team went looking around the company for a new home for the project. Greeley says they found that home in Compaq's iAppliances Group, who had been working on an iPaq desktop PC and a new StrongARM-based handheld pocket PC. The iAppliances pocket device did not have the Itsy's 3-D accelerometer, but it did have the memory and expansion capabilities the Itsy researchers wanted. As Greeley said, "We proposed to them: Hey, let's launch this, what we'll call the Open Handheld program...We'll take our Linux port that we had originally done for Itsy, get it up to the latest revision of the Linux kernel, and at the same time, adapt it to work with the iPaq. This would be a great way to get people innovating on our platform."

As for what might be called the Itsy/iPaq premium, Dick Greeley points to a number of things he believes help set his handheld apart from the rest of the pack. "First of all," he says, "is the processing power. We've got a much faster processor than everybody else." Second, he points to the iPaq screen, which he suggests is at least as good, if not better, than others on the market. "You can look at the screen in bright daylight and still see it," he insists. "You could find your keys in the dark using the screen like a flashlight," Greeley adds by way of example. The iPaq screen also has both a variable brightness control as well as an ambient light sensor that automatically adjusts to the environment. The unit also gets a maximum of 12-14 hours on its Compaq Evo N115 battery, but one of the key features as far as Greeley is concerned is the fact that the operating system (Microsoft Pocket PC standard or Linux, available from the Compaq web site) is stored in flash memory as opposed to being burned into ROM. This gives the user increased ability to load Linux on the iPaq by loading into flash instead of burning a new ROM. Says Greeley, "That proved to be an important thing for us and it's actually made our whole program possible."

Only recently started, it is probably impossible to gauge how much Linux developer interest will flow toward the Itsy/iPaq project. Greeley himself notes that, with regard to the Linux port to the iPaq, "we don't have all the bells and whistles yet," meaning there is no browser and the wireless Ethernet is enroute, but has not yet arrived. The Linux Itsy does feature the X Window System, however, and Greeley expects progress to come quickly. "We've started shipping the new iPaq in the last several weeks and there's been very good demand for them...One of the things we've heard a lot of the last week and a half is a lot of Linux people saying, "Finally! I've got my thing I can play with now! Thank you for following through!"--even though the product is not exactly the same as the Itsy.

Linux is an open source operating system that is a modified clone of the UNIX operating system. Initially, during the 1960s 1980s computer systems were large, bulky and were solely dependent on codes to be functional. A common man cannot run a computer if he is not well aware of the system coding and if he is not part of the government or a university, as these systems were rarely found amongst common people. Geeks and nerds came together to develop faster, easier and more effective systems that would not be limited to large mainframe computers. Bill Gates came up with MS Dos and the GUI interface in the form of Windows. Whereas programming experts came up with a modified and improved version of UNIX, that is the LINUX.

The LINUX today is much different than the LINUX of yester years. No longer do you have to understand codes or learn programming skills in order to work on a LINUX system. But because people have grown to love the GUI system of Windows, the LINUX did not come to be so popular amongst the masses. However, programmers, experienced computer developers and server side users claim the LINUX to be their best operating system. LINUX now has strong security levels, and works excellent as a server and hosting services. However, for the common home based user, the OS still poses a problem, as it seems to be incompatible with a number of software programs, mainly windows based tools.

If you are new to this OS and want to understand real user experiences about this system, it is suggested that you join a LINUX forum. These forums will help you in knowing about the operating system through first hand user experiences. For newbies, LINUX forums could help them with problems of software compatibility, commands/codes etc. For experienced users, a Linux forum is a platform where they can share their knowledge and help beginners to be comfortable with the OS, especially if they have been avid Windows users. It really is tough to be a transformed user of LINUX when all your life, you have been in love with Windows.

LINUX forums will also provide you with a platform where questions pertaining to various LINUX versions will be answered and discussed. There are different categories of Linux on such forums, such as Arch, CentOS, Debian Linux etc. These forums are also an ideal ground for developers who want to create software and programs that could be compatible with the Linux platform. Remember you can use all Linux meant software on Windows, but you cannot use Windows based software on LINUX.

Professional Linux forums also provide comprehensive Linux tutorials that can guide you to operate the system. You can receive numerous solutions to Linux hardware/software compatibility issues that are faced by almost every LINUX user.

If you ever want a review on Linux books, you can find that out on Linux forums too. Because forums are based on user experiences rather than expert opinions/suggestions, it could sometimes be biased. In this case, it is always advised that you consult with a LINUX expert or anyone who knows computer sciences very well. However, you can always find the best advice from expert users on the forum.

It means hosting that is provided on Linux/Unix operating systems platforms. There isn't much difference between these two types of operating systems because Linux/Unix is an improved version of Linux/Unix operating system. When just applying for web hosting companies for web hosting that is based on Linux operating system it doesn't matter which one you are using on your computer as it is commensurable with any operating system. UsabilitySome years ago Linux operating system used to be available only for professionals and if you were not an experienced user you had no future with this OS. In the last couple of years the situation has changed. Providers have done their best to make users' web sites administrating more comfortable and easier. In case you're just a beginner you'll find friendly control panels that include Web-interface. And if you are an experienced user you can control your site by means of shell. ReliabilityExperts claim that Unix-based platform is one of the most reliable ones but it will mainly depend on maintenance stuff professionalism. Thus quality and stability of Linux-based web hosting won't depend on some sudden system bugs and the operating system consistency itself secures your web site operating dependability. FunctionalityIn this area Linux differs the most from other popular platforms. It can handle a lot of processes that happen at the same time. This gives you a possibility to get more from the server. What Scripting Languages Are Available For Unix? Unix supports a wide variety of application languages, more than any other operating system. The most common applications of such kind include C, C++, Shell, Perl, Tcl, Python, Java and PHP. What Databases Does Unix Support? Databases available for Unix are mSQL and mySQL. The one you choose would depend on your own needs and your Host Provider's offers. This is important for you to review when choosing a hosting company.CostLinux operating system was developed by Linus Torvalds as an alternative to other operating systems and is being improved by many specialists all around the world. Most of its versions are free of charge. This circumstance makes Linux-based hosting much cheaper than any other. As for Linux versions they are sometimes called Linux Distributions. The most popular Distributions are RedHat and Mandrake. Which are easy to install have a lot of different utilities and suitable for any web hosting type. Why choose Linux/Unix-based hosting? So, as it was mentioned before using this platform is cheaper and more convenient than others. All existent scripts, like PHP, function best when using the Linux-based web hosting. Linux/Unix based web hosting upgrading possibilities increase when using Shell and Telnet access. The Linux/Unix-based platform is probably the most stable and reliable.