Operating System Comparisons

2681 WordsMar 5, 201311 Pages
Operating System Comparisons PRG/355 February 4, 2013 Operating System Comparisons Table of Contents Introduction 3 Memory Management 3 Process Management 6 File Management 7 Security 8 Conclusion 9 References 11 Introduction An operating system (OS) is software that manages the hardware and software resources of a computer system. Basically an OS is a set of libraries or functions which programs may use to perform specific tasks relating to interfacing with computer system components (The Computer Technology Documentation Project, n.d.). Advantages and disadvantages exist in every operating system. Reviewed in this paper is a comparison of some of the primary responsibilities of popular operating…show more content…
The kernel maintains a list of free pages for each zone. Each zone has its own page allocator that allocates and frees memory as needed. Mac OS X is a little different as compared to the older MAC OS virtual memory. Similar to Windows OS, when Mac OS X needs memory it pushes something currently not needed into a swap file for temporary storage (OSX Daily, 2010). The swap file concept is also known as virtual memory. Mac OS X, because it is built on the UNIX core, relies heavily on swap files and paging for general memory and cache management. Virtual memory, also known as secondary memory or secondary storage, typically refers to hard disk storage and is much slower than main memory. Advantages of virtual memory include; running more than one application at a time, the ability to run larger programs with less RAM, applications may launch faster because of file mapping, and the user does not have to buy more main memory (RAM). Disadvantages of virtual memory include; applications run slower than if loaded into main memory, increased time to switch between applications, less hard drive space for the users use, and some may argue reduced system stability is inherent to virtual memory. Linux’s virtual memory system is responsible for the memory visible to each process. The memory system creates virtual memory on demand and swaps pages in and out of main memory to the disk as needed. Virtual memory is divided into regions called backing. Backing is
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