A virtual machine can exist as a standalone machine or it can exist within a vApp.
A virtual machine is a software computer that, like a physical computer, runs an operating system and applications. The virtual machine consists of a set of specification and configuration files and is backed by the physical resources of a host. Every virtual machine has virtual devices that provide the same functionality as physical hardware are more portable, more secure, and easier to manage. Virtual machines can be standalone, or they can exist within a vApp. A vApp is compound object composed of one or more virtual machines as well as one or more networks.
The following figure shows the different options when creating a virtual machine. You can create a standalone virtual machine. In this case, the virtual machine is directly connected the organization VDC. Or, you can create a virtual machine within a vApp. Ceating a virtual machine inside of a vApp allows you to group together multiple virtual machines and their associated networks. vApps allow you to build complex applications, and save them for future use in a catalog.Virtual Machines are Standalone or within a vApp
Multitasking system · Technically , multitasking is same as multi programming · In a multitasking operating system, s single user can execute multiple programs at the same time · We can also say, multitasking is the system capability to work on more than one job or process at the same time. · It means that whenever a job needs to perform I/O operation, the cpu can be used for execting some other job diagram of multi tasking · There are two type of multitasking : 1. ...
Monolithic Architecture Monolith means composed all in one piece. The Monolithic application describes a single-tiered software application in which different components combined into a single program from a single platform. Components can be: Authorization — responsible for authorizing a user Presentation — responsible for handling HTTP requests and responding with either HTML or JSON/XML (for web services APIs). Business logic — the application’s business logic. Database layer — data access objects responsible for accessing the database. Application integration — integration with other services (e.g. via messaging or REST API). Or integration with any other Data sources. Notification module — responsible for sending email notifications whenever needed. Example for Monolithic Approach Consider an example of Ecommerce application, that authorizes customer, takes an order, check products inventory, authorize payment and ships ordered products. This applicat...
Batch processing system · Batch processing is one of the oldest method of running the programs · The computer in the past were very large in size and their I/O devices were very different from those that are used today. The job processing was not interactive as it is today. · The user did not interact directly with computer system. · The process scheduling , memory management, file management and I/Omanagement functions are quite simple in batch processing system 1. Process scheduling (i.e. allocation strategy for a processor is typically in order of their arrival i.e. first come first served(FCFS)basis. 2. Memory management is done by divi...
Change the priority of a process You can tell the computer that certain processes should have a higher priority than others, and so should be given a bigger share of the available computing time. This can make them run faster, but only in certain cases. You can also give a process a lower priority if you think it is taking up too much processing power. Go to the Processes tab and click on the process you want to have a different priority. Right-click the process, and use the Change Priority menu to assign the process a higher or lower priority. There is typically little need to change process priorities manually. The computer will usually do a good job of managing them itself. (The system for managing the priority of processes is called nice .) Does higher priority make a process run faster? The computer shares its processing time between all of the running processes. This is normally shared intelligently, so programs that are doing more ...
C omparison between real time and time sharing operating system P rotection and s ecurity • Protection refers to a mechanism for controlling the access of program s processes, or users to the resources defined by computer system. • The concept of protection came with the advent of multiprogramming where several processes compete for the use of CPU. • the purpose was to confine each users program to its assigned areaof memory so that the programs cannot interface and harm each other. • Protection in main memory is particularly important because of address translation. The purpose of protection is to allow concurrently running process to share the common physical address space. • Protection also ensure that only process that have gained proper authorization from the operating system can operate on memory segment , the CPU, files and other resources.
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