Version Of Operating System Research Articles

File system virtual appliances

File system virtual appliances (FSVAs) address the portability headaches that plague file system (FS) developers. By packaging their FS implementation in a virtual machine (VM), separate from the VM that runs user applications, they can avoid the need to port the file system to each operating system (OS) and OS version. A small FS-agnostic proxy, maintained by the core OS developers, connects the FSVA to whatever OS the user chooses. This article describes an FSVA design that maintains FS semantics for unmodified FS implementations and provides desired OS and virtualization features, such as a unified buffer cache and VM migration. Evaluation of prototype FSVA implementations in Linux and NetBSD, using Xen as the virtual machine manager (VMM), demonstrates that the FSVA architecture is efficient, FS-agnostic, and able to insulate file system implementations from OS differences that would otherwise require explicit porting.

The Effects of FreeSurfer Version, Workstation Type, and Macintosh Operating System Version on Anatomical Volume and Cortical Thickness Measurements

FreeSurfer is a popular software package to measure cortical thickness and volume of neuroanatomical structures. However, little if any is known about measurement reliability across various data processing conditions. Using a set of 30 anatomical T1-weighted 3T MRI scans, we investigated the effects of data processing variables such as FreeSurfer version (v4.3.1, v4.5.0, and v5.0.0), workstation (Macintosh and Hewlett-Packard), and Macintosh operating system version (OSX 10.5 and OSX 10.6). Significant differences were revealed between FreeSurfer version v5.0.0 and the two earlier versions. These differences were on average 8.8±6.6% (range 1.3–64.0%) (volume) and 2.8±1.3% (1.1–7.7%) (cortical thickness). About a factor two smaller differences were detected between Macintosh and Hewlett-Packard workstations and between OSX 10.5 and OSX 10.6. The observed differences are similar in magnitude as effect sizes reported in accuracy evaluations and neurodegenerative studies.The main conclusion is that in the context of an ongoing study, users are discouraged to update to a new major release of either FreeSurfer or operating system or to switch to a different type of workstation without repeating the analysis; results thus give a quantitative support to successive recommendations stated by FreeSurfer developers over the years. Moreover, in view of the large and significant cross-version differences, it is concluded that formal assessment of the accuracy of FreeSurfer is desirable.

Evaluating IPv6 in Peer-to-Peer 802.11n Wireless LANs

IPv6 is built into the latest versions of Microsoft Windows and Linux-based operating systems. It's expected to replace the current IPv4 and solve its numerous problems, such as address exhaustion, security, and mobility. However, implementing IPv6 will have drawbacks, such as lower bandwidth, so it's important to determine which modern operating systems will give the best bandwidth performance over IPv6 networks.

Classification of software patches: a text mining approach

AbstractInstallation of maintenance patches in operational software systems is a source of significant expenditure and resource consumption. Managers often have to find a balance between publicly announced vulnerabilities and/or possible destabilization of existing applications, while making decisions regarding patch roll out to all systems. We propose a classification scheme for maintenance patches and examine the effects of patch category on the internal characteristics of a software system. Text mining the patch releases of 77 successive versions of the Linux operating system, we extend previous categorization schemes to maintenance patches. This granularity level offers a view of the aggregate nature of the tasks performed in each version. An unsupervised learning technique, cluster analysis associated with Text mining, reveals that there are three identifiable categories in Linux patch files. Based on the maintenance keywords in each category, we label them as: corrective, perfective and adaptive patches. Further analysis of the effects of patch category on the structural complexity and the time to next release indicates that perfective patches are associated with a reduction in the complexity and frequency of patch release. Categorization at the patch level is useful for managers, since changes made to operational software systems are through patches. Determining the nature of a patch can assist managers in planning version roll out and testing criterion. Copyright © 2010 John Wiley & Sons, Ltd.

Quality of service shared cache management in chip multiprocessor architecture

The trends in enterprise IT toward service-oriented computing, server consolidation, and virtual computing point to a future in which workloads are becoming increasingly diverse in terms of performance, reliability, and availability requirements. It can be expected that more and more applications with diverse requirements will run on a Chip Multi-Processor (CMP) and share platform resources such as the lowest level cache and off-chip bandwidth. In this environment, it is desirable to have microarchitecture and software support that can provide a guarantee of a certain level of performance, which we refer to as performance Quality of Service . In this article, we investigated a framework would be needed to manage the shared cache resource for fully providing QoS in a CMP. We found in order to fully provide QoS, we need to specify an appropriate QoS target for each job and apply an admission control policy to accept jobs only when their QoS targets can be satisfied. We also found that providing strict QoS often leads to a significant reduction in throughput due to resource fragmentation. We proposed throughput optimization techniques that include: (1) exploiting various QoS execution modes, and (2) a microarchitecture technique, which we refer to as resource stealing, that detects and reallocates excess cache capacity from a job while preserving its QoS target. We designed and evaluated three algorithms for performing resource stealing, which differ in how aggressive they are in stealing excess cache capacity, and in the degree of confidence in meeting QoS targets. In addition, we proposed a mechanism to dynamically enable or disable resource stealing depending on whether other jobs can benefit from additional cache capacity. We evaluated our QoS framework with a full system simulation of a 4-core CMP and a recent version of the Linux Operating System. We found that compared to an unoptimized scheme, the throughput can be improved by up to 47%, making the throughput significantly closer to a non-QoS CMP.

EU Obligation to the TRIPS Agreement: EU Microsoft Decision

In Microsoft v. Commission, Microsoft was ordered by the European Court of First Instance (CFI) to license interface information to its competitors on reasonable terms and to supply a fully functioning version of Windows Personal Computer Operating System without Windows Media Player. Microsoft claimed that the remedies infringed the minimum standards of IP protection provided by the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS). However, the CFI refused to examine the TRIPS provisions, on the basis that international agreements do not prevail over primary Community law, and in any case, the TRIPS agreement permits members to restrain anti-competitive abuse of IP rights. This article examines the issues that arise from this position: first, is the Microsoft decision TRIPS compliant? Secondly, to what extent is the EU bound to its obligations under the TRIPS Agreement? The article highlights the lack of a clear-cut hierarchy of norms and illustrates how EU law is placed within a multi-layered governance structure involving national law and international law. The article finds that the EU does not engage in consistent interpretation or application of the TRIPS provisions.

Dynamic recreation of kernel data structures for live forensics

The role of live forensics in digital forensic investigations has become vital due to the importance of volatile data such as encryption keys, network activity, currently running processes, in memory only malware, and other key pieces of data that are lost when a device is powered down. While the technology to perform the first steps of a live investigation, physical memory collection and preservation, is available, the tools for completing the remaining steps remain incomplete. First-generation memory analyzers performed simple string and regular expression operations on the memory dump to locate data such as passwords, credit card numbers, fragments of chat conversations, and social security numbers. A more in-depth analysis can reveal information such as running processes, networking information, open file data, loaded kernel modules, and other critical information that can be used to gain insight into activity occurring on the machine when a memory acquisition occurred. To be useful, tools for performing this in-depth analysis must support a wide range of operating system versions with minimum configuration. Current live forensics tools are generally limited to a single kernel version, a very restricted set of closely related versions, or require substantial manual intervention. This paper describes techniques developed to allow automatic adaptation of memory analysis tools to a wide range of kernel versions. Dynamic reconstruction of kernel data structures is obtained by analyzing the memory dump for the instructions that reference needed kernel structure members. The ability to dynamically recreate C structures used within the kernel allows for a large amount of information to be obtained and processed. Currently, this capability is used within a tool called RAMPARSER that is able to simulate commands such as ps and netstat as if an investigator were sitting at the machine at the time of the memory acquisition. Other applications of the developed capabilities include kernel-level malware detection, recovery of processes memory and file mappings, and other areas of forensics interest.

First Edition Unix: Its Creation and Restoration

Until recently, the earliest versions of the Unix operating system were believed to have been lost completely. In 2008, however, a restoration team from the Unix Heritage Society completed an effort to resurrect and restore the first edition Unix to a running and usable state from a newly discovered listing of the system's assembly source code.

On enhancing GridFTP and GPFS performances

One of the most demanding tasks which Computing in High Energy Physics has to deal with is reliable and high throughput transfer of large data volumes. Maximization and optimization of the data throughput are therefore key issues which have to be addressed by detailed investigations of the involved infrastructures and services.In this note, we present some transfer performance tests carried out at the INFN-CNAF Tier-1 center, using SLC4 64-bit Grid File Transfer Protocol (GridFTP) servers and a disk storage system based on the General Parallel File System (GPFS) from IBM. We describe the testbed setup and report the measurements of throughput performances in function of some fundamental variables, such as number of parallel file and number of streams per transfer, concurrent read and write activity and size of data blocks transferred.During this activity, we have verified that a significant improvement in performances of the GridFTP server can be obtained using 64bit version of Operating System and GPFS from IBM.

Path-Length as a Metric for Subject Motion

Path-Length as a Metric for Subject Motion

Using iPodLinux in an introductory OS course

This paper describes a proof of concept for introducing iPods and iPodLinux into a one-semester introductory undergraduate operating systems course. iPodLinux is a version of the Linux operating system modified to run on iPods. We added a project to our course in which the students modified the iPodLinux kernel, and we supplemented lectures by discussing specifics of the Linux implementation as they relate to general operating systems concepts. We feel the course was much improved by these additions, with no substantive omission of regular material. Student response was very enthusiastic, and we feel the new material enhanced their course experience by providing a component that was empowering and helped to further improve their knowledge and skills.

New Software, Disposable Software, and Second Life

THE FUTURE is a complicated place, as I've said many times before. Unfortunately, it is getting worse than even I could imagine. I used to think that I was a power user of all kinds of technology, but today that is no longer possible. There is just too much complexity for any one person to master. One of the relatively recent happenings that has complicated matters is the advent of what I call By that term I mean any software that becomes obsolete in a very short time. Both Microsoft and Apple now make disposable software and have done so for several years. Let me explain. Every 12 to 24 months, Apple releases a new version of the Mac operating system (OS X). The most recent version is called Microsoft does likewise for PCs. Leopard has many enhancements of the interface and offers specific features that help to automate work flow. However, before installing Leopard, you absolutely must go through all the other software you own to find out if it is compatible with Leopard. Plan on spending the better part of a day completing this task. A friend just installed Leopard and quickly found that his version of Photoshop, as well as other programs, did not work on Leopard. He further learned that no upgrade was available, so he would need to purchase an entirely new version of many of his programs. So within less than two years, his recent version of OS X had become disposable and with it much of his other software. There goes another hundred dollars for Leopard and a few hundred more for Photoshop. In past columns I have mentioned Keynote, Apple's great presentation program, which is bundled with Pages to make what Apple calls iWork '06. In late 2007, Apple came out with iWork '08. A few days ago, I wanted to use Keynote to create a presentation that I could export as a QuickTime movie. The export failed. I had recently upgraded to QuickTime 7.2 player, which I think was the problem. Now I will probably need to purchase QuickTime 7.2 Pro for about $30. And because there is no upgrade path for Keynote '06, there goes another hundred dollars. You can avoid problems like those above if you keep in mind that the software in your computer must work together and that old and new programs might not play well together. To avoid problems, never upgrade any software unless you are prepared to upgrade nearly all of your software. You can simply keep using the old stuff that works. Now that I have given Apple some press, let me turn my attention to Microsoft's latest blunder: Vista. If you thought Apple liked to upset the apple cart occasionally, consider Vista, Microsoft's newest version of its Windows operating system. A lot of older PC software is not compatible with Vista. Here are a few words from the Microsoft Vista website: Most programs written for Windows XP also work in this version of Windows, but some older programs might run poorly or not at all. If a program written for an earlier version of Windows doesn't run correctly, use the Program Compatibility Wizard to change the compatibility settings for the program. To change settings for a program manually, use the individual program's Compatibility tab. If changing the settings does not fix the problem, go to the program manufacturer's website to see if there is an update for the program. Here is an abbreviated list of the settings you might have to tweak to get older software to run (minus any description of what they do and how to use them): compatibility mode, run in 256 colors, run in 640 x 480 screen resolution, disable visual themes, disable desktop composition, disable display scaling on high DPI settings, privilege level, and show settings for all users. How bad is the Vista dilemma? Already I have students who are frustrated because I cannot open their e-mailed homework, which they wrote in Word 2007. I simply have to ask them to please bring me a printed copy. …

Real-time data acquisition and feedback control using Linux Intel computers

This paper describes the experiences of the DIII-D programming staff in adapting Linux based Intel computing hardware for use in real-time data acquisition and feedback control systems. Due to the highly dynamic and unstable nature of magnetically confined plasmas in tokamak fusion experiments, real-time data acquisition and feedback control systems are in routine use with all major tokamaks. At DIII-D, plasmas are created and sustained using a real-time application known as the digital plasma control system (PCS). During each experiment, the PCS periodically samples data from hundreds of diagnostic signals and provides these data to control algorithms implemented in software. These algorithms compute the necessary commands to send to various actuators that affect plasma performance. The PCS consists of a group of rack mounted Intel Xeon computer systems running an in-house customized version of the Linux operating system tailored specifically to meet the real-time performance needs of the plasma experiments. This paper provides a more detailed description of the real-time computing hardware and custom developed software, including recent work to utilize dual Intel Xeon equipped computers within the PCS.

Are New Versions of PC Operating Systems More or Less Reliable than Older Versions?

Off-the-shelf operating systems (OSs) are increasingly being used in critical systems. These OSs include members of the Microsoft Windows family and various distributions of the increasingly popular Linux OS. Reliability estimates of these standard off-the-shelf OSs are needed so, in order to evaluate the reliability of these systems, data were collected from product support Web sites. In contrast to previous studies, the reliability of Windows NT Workstation 4.0 was found to exceed that of Windows 2000 Professional. In addition it was found that the reliability of these systems degraded over the product lifecycle. The reliability of four versions of Red Hat Linux was evaluated, and although the Red Hat OSs were more reliable than the Windows products, they exhibited the same pattern of reliability degradation across versions and, to a lesser extent, within the product lifecycle. The potential causes of these trends are examined as well as some of their implications. Copyright © 2005 John Wiley & Sons, Ltd.

Dynamic Estimation of Task Level Parallelism with Operating System Support

The amount of Task Level Parallelism (TLP) in runtime workload is useful information to determine the efficient usage of multiprocessors. This paper presents mechanisms to dynamically estimate the amount of TLP in runtime workloads. Modifications are added to the operating system (OS) to collect information about processor utilization, task activities, from which TLP can be calculated. By effectively utilizing the Time Stamp Counter (TSC) hardware, the task activities can be monitored at fine time resolution, resulting in capability of estimation of TLP at fine granularity. We implement the mechanisms on a recent version of Linux OS. Evaluation results indicate that the mechanisms can estimate TLP accurately for various kinds of workloads with small overheads.

Real-Time Operating Systems

Real-time operating systems are an integral part of complex real-time systems. Three general categories of real-time operating systems exist: small, proprietary kernels, real-time extensions to commercial timesharing operating systems, and research kernels. This paper discusses each of these areas focusing on how each of these classes deal with predictability. It is argued that the small, proprietary kernels are predictable, but offer little help to the real-time systems designer and implementor in producing predictable applications. Real-time versions of commercial operating systems like UNIX and Mach offer greater implementation support, but are, in general, NOT predictable themselves nor offer enough support to applications which require predictability. This, of course, does not mean that there is no way to achieve predictability with these operating systems. It is possible to achieve predictability by very careful design, by using a very limited subset of the overall features provided, and by proving that the features being used for predictability cannot in any way be impacted by any other part of the system. Finally, research kernels are attempting to provide greater design, implementation and evaluation support together with predictability for both the operating system and the application.

DIII–D tokamak control and neutral beam computer system upgrades

This paper covers recent computer system upgrades made to the DIII–D tokamak control and neutral beam computer systems. The systems responsible for monitoring and controlling the DIII–D tokamak and injecting neutral beam power have recently come online with new computing hardware and software. The new hardware and software have provided a number of significant improvements over the previous Modcomp AEG VME and accessware based systems. These improvements include the incorporation of faster, less expensive, and more readily available computing hardware which have provided performance increases of up to a factor 20 over the prior systems. A more modern graphical user interface with advanced plotting capabilities has improved feedback to users on the operating status of the tokamak and neutral beam systems. The elimination of aging and non supportable hardware and software has increased overall maintainability. The distinguishing characteristics of the new system include: (1) a PC based computer platform running the Redhat version of the Linux operating system; (2) a custom PCI CAMAC software driver developed by general atomics for the kinetic systems 2115 serial highway card; and (3) a custom developed supervisory control and data acquisition (SCADA) software package based on Kylix, an inexpensive interactive development environment (IDE) tool from borland corporation. This paper provides specific details of the upgraded computer systems.

Seasonal Shoppers' Guide

I have thought about this annual column for quite some time, and I don't think I'm particularly inspired this year. The reason is my staid conviction that professional educators should use powerful tools indeed, and I realize that such power tools often cost a goodly sum. I would really like to give you a nice list of suggestions for gifts that cost between $30 and $100, but honestly, I don't know of many. So I resign myself to the old adage about spending money, You're worth it. With this disclaimer in mind, here is my seasonal techie's wish list. Internet Connection I hate telecommunications in any form; it has always been my nemesis. There are just too many variables that can wrong - like your computer's operating system version number, modem type and speed, all kinds of protocols, the quality of your phone line, and on and on. Thus, at the top of my seasonal wish list is a local, fast, reliable Internet connection that somebody else is responsible for making work. To date, I have had very little luck with my university with my state's free net connection, and with my America Online account. I recommend that you seasonal shoppers do one of four things: register with a local Internet Service Provider (ISP), talk with your local telephone company, try out ATT it'll cost $10 to $40 a month. But what I'd like best is a really fast connection. I think I'll have to bite the bullet and get a fast cable modem - about $38 per month plus an equipment deposit. My local cable company (Continental Cable, now owned by US West) has modems with ISDN speed from me to them (128 kbs) and near-Ethernet speeds from them to me (4-6 MB/sec). So you see you can get a very fast pipe to your home computer. If you want to shop for a fast, reliable Internet talk with others who already have one and start shopping yesterday. You might note that this girl has a monthly pay as you go feature. Incidentally, my very favorite modem is a Practical Peripherals 28.8 kbs modem (about $400) with a four-line LCD screen that lets you know exactly what the modem is doing - in English! A New Computer Telling you what kind of computer to buy is about as ridiculous as telling you what kind of car to drive, so I won't. What I can tell you is that I specify, buy, or configure several hundred computers a year. At present, I especially like the idea of Motorola brand Macs that come with a five-year warranty and Dell brand PCs with an extended three-year warranty. (Pay a little extra; it's worth it.) During the summer of 1995, I installed 225 PowerMac 5200/75 LCs. Now there is a recall that makes about 80 of them require serious repair work. Friends have had similar problems with Zenith brand PCs and Power Computing brand Macs. From now on, I intend to buy machines with long warranties and on-site service, since I don't want to ship someone a computer and have them ship it back to me a month or more later. Apparently, the drive to get the product out the door fast and the complexity of the modem microcomputer make rock-solid reliability a thing of the past. The last bit of advice on buying a new computer is: buy institutional-grade computers for home; don't buy home-grade machines. Instead of dropping by the local department store or buyer's club warehouse, I recommend that you check out the educator purchase plans offered by most of the big computer makers. Generally, computers sold to schools and universities are industrial-grade machines with metal cases instead of plastic, better industrial design, and stronger circuit boards. (If you know a good computer repair person, ask him or her about how the computer you want to buy looks on the inside.) I hate to name names, but I would shy away from home-grade machines like Packard Bells, IBM Aptivas, and Apple Performas or LCs. (Of late, Apple deserves a good cussing for selling such home-grade machines as Performas and LCs to schools. …

Implementing multilingual touch-screen audio-CASI applications

Audio computer-assisted self-interviewing (audio-CASI) technologies have become standard tools for collecting information on sensitive measures. However, while the method is commonly applied in the English language, its use is less prevalent in non-English language data collection efforts. One reason for the low occurrence of non-English audio-CASI applications is the relatively slow conversion of audio-CASI software to the nonstandard fonts required to display some languages (e.g., Russian, Chinese). Every written language requires an alphabet and a variety of fonts designed to display the special symbols and notations used by that language. However, early versions of PC operating systems were not flexible in their capacity to support nonstandard fonts. That is no longer the case with the development of more advanced operating systems such as Windows XP. This paper describes a versatile method for implementing audio-CASI technologies using any defined font and therefore any alphabet for which a font exists. This method relies on the capabilities of Rich Text Format for representing the visual or screen display component of the survey. Rich Text Format is supported by a variety of text editors and word processing packages, including Word and Word Perfect. It can be implemented in any software system with Rich Text Edit Control (RTEC). We describe a general process that exploits the capabilities of RTEC to efficiently implement multilingual audio-CASI applications, and demonstrate that process using four distinct languages.

Speakout Unite or Face Irrelevance

Last May, Sun Microsystems Inc. (Santa Clara, CA) and Red Hat Inc. (Raleigh, NC), which markets a version of the Unix operating system, announced that they would distribute each other's products worldwide. It is a hopeful sign for the information technology industry, but not nearly grand enough. In this article, the author argues that what we really need is for those two companies, along with Apple Computer Inc. (Cupertino, CA), to merge into a hardware-and-software colossus.