Category Archives: Operating Systems

Software concepts of Computer

Before starting the software concepts, let us take a brief look into the components of computer. Components of Computer: A computer system has 3 components namely: Hardware, Software, and Users. These are explained as following below. 1. Hardware: Hardware consists of the physical devices. Basically, hardware is the interconnection of devices and study related to how to deal… Read More »

Difference between Full Virtualization and Para-virtualization

Process of abstracting underlying hardware components from software is the primary concept behind virtualization. 1. Full Virtualization In full virtualization, a single host operating system allows the execution of more than one guest operating system in an isolated way. This is performed using direct execution and binary translation. Here, host OS is unaware about virtualization. It is the… Read More »

Storage Structure memory

Storage structure consists of registers, main memory, and magnetic disk is only one of many possible storage systems. There are also cache CD ROM, magnetic takes, and so on. Each storage system based one storing system also for holding until it is retrieved at a later time. Differences in many storage devices are based on speed, cost, size,… Read More »

What is Software and its Types ?

Software is nothing but a program or collection of programs that perform a specific task. Software is a bridge between user and computer hardware. Softwares directs the peripheral devices on how to perform the task which is specified for that software. There are two main types of Software given as Follows:     System Software Application Software These… Read More »

Multilevel Paging in Operating System

A page table is a data structure used by virtual memory system in a computer operating system to store the mapping between the virtual addresses and physical addresses. Multilevel page tables are split into two or more levels.The multi-level page tables are tree-like structures to hold page table. The entries of the level-0 page table are pointers to… Read More »

Deadlock in Operating System

In an operating system, deadlock is a situation where a set of processes are blocked because each process is holding a resource and waiting for another resource acquired by some other process. For example, in the below diagram, Process 1 is holding Resource 1 and waiting for resource 2 which is acquired by process 2, and process 2… Read More »

Introduction of System Call

To understand system calls, first one needs to understand the difference between kernel mode and user mode of a CPU. Every modern operating system supports these two modes. In computing, a system call is the programmatic way in which a computer program requests a service from the kernel of the operating system it is executed on. A system… Read More »

Deadlock Detection And Recovery

Deadlock Detection and Deadlock recovery are important tasks of OS. If deadlocks are not avoided, then another approach is to detect when they have occurred and recover somehow. These are explained as following below. 1. Deadlock Detection : If resources have single instance : If cycle exist in the Resource Allocation Graph, then there exist deadlock in the… Read More »