Difference between revisions of "Roles of the Operating System"
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| − | You would understand how difficult to operate a computer in earlier days, if you have known about the [[history of operating system]]. So the [[Operating systems]] are designed to provide uniform abstraction across multiple applications and the fair sharing of resources. The operating system communicates both with the different hardware components of the computer as well as additional software applications the user may add on to the computer. [[Operating systems]] are also act as a vital part of the computing experience. Take [[Microsoft’s Operating systems]] as examples, they have come a long way since the days of DOS and Windows 3.0, and they are constantly changing and evolving. It’s only been about twelve years since Windows 95 was released, and the changes from 95 to Vista are extraordinary. It will be interesting to see what’s next. | + | You would understand how difficult to operate a computer in earlier days, if you have known about the [[History of Operating Systems|history of operating system]]. So the [[Operating systems]] are designed to provide uniform abstraction across multiple applications and the fair sharing of resources. The operating system communicates both with the different hardware components of the computer as well as additional software applications the user may add on to the computer. [[Operating systems]] are also act as a vital part of the computing experience. Take [[Microsoft’s Operating systems]] as examples, they have come a long way since the days of DOS and Windows 3.0, and they are constantly changing and evolving. It’s only been about twelve years since Windows 95 was released, and the changes from 95 to Vista are extraordinary. It will be interesting to see what’s next. |
|...by students=<em>How is software made?</em> | |...by students=<em>How is software made?</em> | ||
Revision as of 00:49, 30 November 2008
COMP1260 > Roles of the Operating System
IntroductionYou would understand how difficult to operate a computer in earlier days, if you have known about the history of operating system. So the Operating systems are designed to provide uniform abstraction across multiple applications and the fair sharing of resources. The operating system communicates both with the different hardware components of the computer as well as additional software applications the user may add on to the computer. Operating systems are also act as a vital part of the computing experience. Take Microsoft’s Operating systems as examples, they have come a long way since the days of DOS and Windows 3.0, and they are constantly changing and evolving. It’s only been about twelve years since Windows 95 was released, and the changes from 95 to Vista are extraordinary. It will be interesting to see what’s next.
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...by studentsHow is software made? |
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Common roles of the Operating System
Role #1: Provide resourse
What is a resource? • Anything valuable (e.g., CPU, memory, disk) Advantages of standard library • Allow applications to reuse common facilities • Make different devices look the same • Provide higher-level abstractions Challenges • What are the correct abstractions? • How much of hardware should be exposed
Role #2: Resource coordinator
Advantages of resource coordinator • Virtualize resources so multiple users or applications can share • Protect applications from one another • Provide efficient and fair access to resources Challenges • What are the correct mechanisms? • What are the correct policies?
Operating System's Role is Changing
The role of the OS in a virtual appliance becomes more about supporting applications. “In Windows and Linux, for example, the applications are coded to those APIs. Over time, there could be operating systems targeting different kinds of applications,” Rosenblum said. “Effectively if you look at reliability and security, you want to simplify, have an environment where can lop off everything not being used. When people start deploying OSs this way, such as for SAP or Oracle applications, you just want to have anOS that delivers what you need. With Linux and Windows you get the whole thing.”
The shift began in the 1990s, as application developers moved away from traditional, proprietary client/server architectures and started to employ OS-neutral development frameworks like Java or open-source development platforms that afforded them more control over application interfaces. Yet despite running in these smaller, more flexible application containers, customer still needed to run the software on a full-service, general purpose OS. They may have regained some control over the application interfaces, but they were still reliant on a fully functional OS to provide all the device compatibility and the accompanying certifications and qualifications.
Virtualization provides the missing piece to break the interlock, and as it becomes pervasive, the role of the OS will fundamentally change. Once you have a pervasive virtualization layer that focuses exclusively on managing all the underlying hardware and can run any OS, developers will finally be able to adapt and integrate the operating system as a part of their application, ship both of those together as a virtual machine and be confident it can run in any environment. Instead of having a general purpose OS underneath their applications, ISVs can strip down the OS of all its excessive functions (and corresponding security holes), make whatever modifications they need to better support their applications, and simply inherit all the hardware qualifications of the virtualization layer. This, in many ways, is what appliance vendors do when they ship a packaged hardware solution with a custom OS for a custom application – the model provides a simple, low cost of management solution but also requires purchasing custom hardware. As virtualization becomes pervasive, any ISV can bring these same benefits by shipping their software as virtual appliances.
