CSE Sem4

Que.1      What is Operating System? explain any one types of operating system Operating System –  Definition:    An operating system is a program that controls the execution of application programs and acts as an interface between the user of a computer and the computer hardware. A more common definition is that the operating system is the one program running at all times on the computer (usually called the kernel), with all else being application programs. Types Of O.S:- 1 Batch Operating System . This type of operating system does not interact with the computer directly. ... 2 Time-Sharing Operating Systems . Each task is given some time to execute so that all the tasks work smoothly.  3 Distributed Operating System .  4 Network Operating System . 5 Real-Time Operating System . Time-Sharing Operating Systems –   Each task is given some time to execute so that all the tasks work smoothly. Each user gets the time of CPU as they use a single ...

Que:-1      What is virtualization? Explain the benefits of virtualization. Ans:-       Virtualization is a powerful tool that helps  relieve administrative overhead while increasing cost optimization, scalability, and efficiency . Benefits:- Slash your IT expenses. Reduce downtime and enhance resiliency in disaster recovery situations. Increase efficiency and productivity. Control independence and DevOps. Move to be more green-friendly (organizational and environmental) Que:-2  Explain pure virtualization in brief. Ans:- Operating System Virtualization is also known as OS-Level Virtualization Technology, which runs on the OS Layer. Pure virtualization process is when multiple operating systems are run on a single computer system.. Uses:- Used for virtual hosting environment. Used for securely allocation of finite hardware resources among a large number of distrusting users. System administrator uses it to integrate s...

Que:-1      What do you mean by security? Discuss in brief access control list. Ans:- Security OS security  refers to specified steps or measures used to protect the OS from threats, viruses, worms, malware or remote hacker intrusions. Access control list Most of domains have no access at all to most objects, so storing a very large, mostly empty, Access matrix is a waste of disk space. Two methods are practical; the first is storing the matrix by rows and the second method is storing the matrix by columns, and then storing only the nonempty elements. The two approaches are surprisingly different. The first technique consists of associating with each object an (ordered) list containing all the domains that may access the object, and how. This list is called the Access Control List or ACL. Here we see three processes A, b, and C, each belonging to a different domain. There are three files F1, F2, and F3. For simplicity, we will assume that each domain corresponds to e...

Que:-1      Explain the terms : Race Condition, Critical Section and Starvation. Ans:-      Race Condition A race condition is a situation that may occur inside a critical section. This happens when the result of multiple thread execution in critical section differs according to the order in which the threads execute. Race conditions in critical sections can be avoided if the critical section is treated as an atomic instruction. Also, proper thread synchronization using locks or atomic variables can prevent race conditions. Critical Section The critical section in a code segment where the shared variables can be accessed. Atomic action is required in a critical section i.e. only one process can execute in its critical section at a time. All the other processes have to wait to execute in their critical sections. Starvation is a condition where a process does not get the resources it needs for a long time because the resources are being allocated to other pr...

 Que:-1      What is Concurrency? Explain it with example.  Ans:-      It refers to the execution of multiple instruction sequences at the same time.  It occurs in an operating system when multiple process threads are executing concurrently.  These threads can interact with one another via shared memory or message passing.  Concurrency results in resource sharing, which causes issues like deadlocks and resource scarcity.  It aids with techniques such as process coordination, memory allocation, and execution schedule to maximize throughput. Que:-2      Explain Message Passing with example. Ans:- Message Passing  provides a mechanism to allow processes to communicate and to synchronize their actions without sharing the same address space. For example  − chat programs on World Wide Web. Now let us discuss the message passing step by step. Step 1  − Message passing provides two operations which are as ...