Computer Hardware and Software
Posts tagged Linux
Explained: Garbage Collection
Jul 22nd
Garbage Collection is the concept of collecting useless “dereferenced” memory, and freeing it for re-use by the system. De-referenced resources are those objects that are no longer in use by the program but are still allocated for use by it.
Languages like C/C++ could allow programmers to directly interact and play with memory, a responsibility that is often so abused that it does more harm than good… Problems arise when people recklessly allocate large system resources and the due to some mis-management the allocated memory is never freed. This leaves large chunks of unreacheable memory locations that ultimately cause “Memory Leaks”. In comes the invention by John McCarthy, which shoulders the responsibility of memory management by de-allocating memory that is not in use by the program anymore. While the concept was initially developed for LISP only, now it has spread to a variety of High Level Languages, including updated versions of C\C++ themselves.
C++/CLI (Common Language Infrastructure), which is Microsoft’s language specification has provision for both manual and automated memory management.
Garbage collector is the term used to represent automatic memory management by the system. Garbage collector scans the runtime environment for objects that are accessible directly or indirectly via references. Then it proceeds to discard all remaining objects. Typically, an object’s memory is reclaimed when the number of references to it reaches zero. These scans are done in cycles, which are started automatically by the Garbage collector or when explicit calls are made to it.
Garbage collection does not guarantee immunity from memory leaks, and obviously requires a considerable percentage of system resources to run, but definitely helps programmers who have to deal with a lot of memory in their projects. Garbage collection is not commonly used in embedded projects due to their already small resource size but are available on certain platforms like .NET Micro Framework and Java-ME.
Have you made your decision to be a Mac or a PC?
May 31st
This is a video review of Mac versus Windows which shows both – the good and the bad – sides of PCs and Macs:
<video>
Personally I made my decision to be a PC because I love to have control over every little part of the OS (using OpenBSD, Ubuntu Netbook Edition and various Windows).
What are you? (Mac, PC or both?) Please comment!
Update: Should colleges start giving Apple’s iPad to students?
May 22nd
This morning I wrote about all the discussions to the question Should colleges start giving Apple’s iPad to students?
But since this time there were many important news-releases surrounding the Apple iPad.
For example data now points that the iPad has become (or always was, given its short life thus far) so popular that it is on the right track to outsell the venerable Mac, Apple’s regular computing line. According to an analyst Apple is selling some 200,000 iPads a week, versus a mere 110,000 Macs in the same time frame.
The iPad is of course a new product, and slower sales are to be expected once the full global roll out has been completed and enough time has passed to fill initial demand. That will take weeks, if not months. At 200,000 a week, Apple will have moved at least another million iPads.
The shocking statistic that has the tech world in an uproar is that some 20% (1 in 5) Americans is either “likely” or “somewhat likely” to purchase an iPad. The population of the United States is roughly 300 million, 20% of that number works out to some 60 million. If Apple sold that many iPads at the lowest price point possible, $500, it would bring in some 30 billion USD in revenue.
Seeing those data, people start to think, if maybe the Apple iPad is going to get a mainstream device and draw in a huge amount of PC users not using apple products yet. For sure other manufacturers will be really unhappy with Apple and since they don’t want to loose all of their clients to the Mac or iPhone/iPad, they have to adopt Apple’s new standards and also be sort of nice to them…
I guess this will end in a really huge showdown between Microsoft and Apple. But then there is another question: What about all the other big technology companies like Google, HP/Dell, HTC, and so on. For sure these companies all have their reasons to like neither Apple nor Microsoft but they will have to decide very soon! Or maybe it will go bad for both Microsoft and Apple as you see Google working on their ChromeOS and HP hugging WebOS.
No matter what happens, it is going to “take a bloody end”. I just hope that customers won’t have to suffer too much.
PS: take a look at how I tagged this post..
Sony to block Windows and Linux from all PS3 Systems
Mar 30th
Sony has announced that a new firmware upgrade for the PlayStation 3, to be released on April 1st, will remove the “Install Other OS” option from all versions of the console. The announcement in the company blog cites “security concerns” as the reason for the removal.
The “Install Other OS” option allows users to install Linux on the Sony console, a capability which Sony did not support on the new “Slim” version of the PS3, released in August 2009. At the time Sony explained that adding the feature to the “Slim” PS3 would have added to development and support costs, but assured developers that the feature would not be removed from previous models of the PlayStation 3.
The ability to install Linux had allowed some groups to sell clusters of the games console and run software which made use of the Cell processor for computation. PS3 clusters have been used, for example, for cracking cryptography.
Linux and other operating systems on the PlayStation 3 run within a managed hypervisor which limits access to the physical hardware to prevent hackers from tampering with the console’s content protection features. Although Sony do not specify the precise reasons for the removal of the other OS feature It is possible that the company has found, or been made aware of, vulnerabilities in the hypervisor implementation that allow the content protection to be compromised.
A Reboot Fixed It
Mar 26th
It has become common behavior it today’s IT world to reboot workstations and sometimes even servers when something isn’t working as expected. I myself am as guilty of this as many others 
The joke goes that if a user complains about an IT problem the IT admin should first ask the user if they have rebooted twice.
This seems to have evolved from historical reliability issues in Microsoft’s line of Windows operating systems. These OS’s (mainly the older but still often used versions) and some applications that run on them seem to have so many minor issues that cause long-term uptime and reliability issues and it is impossible to expect users to troubleshoot them. Given this, it has become common to just expect to have to reboot occasionally or when problems arise, and that usually “fixes” the situation.
However, administrators I know from a unix/linux background tend to never ever reboot. In fact, many of them seem to hold their servers’ uptimes as a point of pride. When something goes wrong instead of rebooting immediately they figure out what is wrong and they fix it and usually without a reboot! (yes, some even spend many hours of their free time just to not have to reboot)
The problem arises now that linux is becoming a little bit more mainstream (in some areas – for example secrity technology) and accessible to all sort of users. Given our windows-bred behavior if a problem arises with a linux server we just bounce the box and hope it doesn’t come back… If someone asks about the issue we quickly declare “A reboot fixed it” and move on with our lives. If I received a nickel each time I heard this I could start my own small venture capital fund.
The reality is that you should not have to reboot windows or linux machines. If you are having to rebooting your servers you *do* have a problem and the reboot is not really ”fixing” anything – it’s only removing the symptoms for a period of time. Unless you are prepared to deal with continuous rebooting any other possible side effects I’d advise you do a couple things when problems are encountered:
First, classify the problem very specifically. The problem isn’t that “My computer doesn’t work” or “The internet is down.” What specifically isn’t working? Second, collect as much relevent information as you can and then some. Often “irrelevent” information is quite relevent as the core cause is not always where one expects. Finally, Troubleshoot the issue. If you are unsure how to troubleshoot the issue – DO NOT REBOOT. If you want to fix the issue go find someone who can help you and describe the problem very specifically and give them your gathered information (or maybe fix it yourselfe if you know how to and have the time to research the issue). If you do reboot, you’ve erased all the symptoms and made finding the problem much more difficult.
Windows 7 vs. Ubuntu 9.04 EyeCandy
Mar 2nd
I just found this nice video in Youtube:
You think thats impressive? Me too 
Looks cool – but do you really need all this eyecandy stuff? I like Windows 7 because it is just the right amount of visual cool looking stuff so you are able to work as efficient as possible. But this varies between each person.
PS: I have UBUNTU 9.10 as second multiboot system and it is really helpfull to impress other people
Viruses for Linux mean Linux is getting Mainstream?
Jan 30th
Freetards have long held the belief that Linux is immune to viruses. None of them will be able to give a clear reason as to why this is, but they generally believe that its because Linux is so much better written. They ignore the fact that with a 1% marketshare and unstable API, Linux is a very small moving target that will garner little press should a virus actually strike.
However, when a malicious virus was discovered in several screen savers on an Ubuntu theme site the freetard spin went into overdrive. Some going as far as to claim that viruses are an indication that Linux has gone mainstream.
“In my eyes this is just an indication that Linux has made it big. This should be a milestone for distributions.”
You can’t have it both ways freetards! You can’t tell everyone to use Linux because its more secure and doesn’t get viruses, then immediately turn around and claim that the viruses are a good sign.
PS: If you don’t agree with this, just post a link to this blog somewhere and then discuss it with other people. If you still think, this is wrong, feel free to write a comment 
10 things that have rocked the world of Linux in a significant way
Dec 19th
Linux has influenced the IT-World a lot! Even if many Companies aren’t happy about it, I am really happy to have such a great free and open source Unix-like Operating System.
That is why I made a little collection of 10 things that stand out in everyone’s minds as having rocked the world of Linux in a significant way.
Regarding UserAccounts in ReactOS
Dec 17th
Hi,
many of you know we don’t even support multiple Users at all, but I made some thoughts these days what way would be the best. I looked at the Linux and Windows ways and see pros and cons in both. Lets Compare them. Read the rest of this entry »
Google Chromium OS source code published!
Dec 15th
Google Chrome OS is now open sourced as “Chromium OS”. This means code is free, accessible to anyone and open for contributions. Chromium OS project includes current code base, user interface experiments and some initial designs for ongoing development, Google.
- It’s all about web. All apps are web apps. Entire experience takes place within browser and there’re no conventional desktop app, means users don’t have to deal with installing, managing and updating programs.
- Second, because all apps live within browser, there’re significant benefits to security. Chrome OS doesn’t trust apps you run. Each app’s contained within a security sandbox making it harder for malware and viruses to infect your computer. Chrome OS Security Overview.
- Chrome OS is a lightweight Linux distribution based on Debian that uses a lot of open-source software: Host AP Linux drivers, PAM (an authentication mechanism), Syslinux (a lightweight bootloader), IBus (Intelligent Input Bus for Linux / Unix OS), ConnMan (Internet connection manager), XScreenSaver and other software.
- Also Google announced, it’s OS will be ready for consumers this time next year. Sign up here for updates or if you like building your operating system from source. Or just come back to this weblog from time to time to get news about Chrome OS!
Here are 3 Videos that give you basic information about the Operating System: