Edgeineers: Operating System

Hi Friends....

Today I am continuing my talk about operating system...

Q. What is the main component of operating system?

Ans.Main component of operating system are kernel and shell

Shell is a interface between application program and kernel whenever application program wants some work to be done. It contacts kernel and kernel inturn perform work with the help of device drivers .thus we can say kernel is an interface between hardaware and shell.

kernel uses device drivers to control microcontroller card of peripherial device and inturn work is being accompalished.

Application Progam -> [Shells ->Kernel ->Device Driver -> Controller Card -> Physical Hardaware]

Q.What is difference between NTFS & FAT32?

Ans. NTFS stands for new technology file system or network technology file system. In NTSF partition size can be of 2 TB or more. and file size can be 16 TB. file/folder encryption is done. and it supports file name character upto 255.

FAT32 stands for File allocation table. in FAT32 partition size can be Upto 2 TB. and file size can be 4 GB. file/folder encryption is not possible in FAT32. and it supports file name character upto 8.3.

Q. what is difference between system call and system program?

Ans. System call is an interface between running procee and O.S. If a process needs a service from O.S. it issues a system call. System call are special APIs provided by OS to let the user manipulate hardware in restricted manner or to do priviledged jobs.

System program is a program provided by the O.S. for some common task. System programs are special program which lies between OS and Application programs. They are closer to kernel as compared to application programs. ex compiler, OS , Editor.

Q. What is virtual memory?

Ans. A virtual memory is a hardware technique where the system appears to have more memory that it actually does. This is done by time-sharing, the physical memory and storage parts of the memory one disk when they are not actively being used.

Q. Why paging is used?

Ans. Paging is solution to external fragmentation problem which is to permit the logical address space of a process to be noncontiguous, thus allowing a process to be allocating physical memory wherever the latter is available.

Q. What is Throughput, Turnaround time, waiting time and Response time?

Ans. Throughput – number of processes that complete their execution per time unit
Turnaround time – amount of time to execute a particular process
Waiting time – amount of time a process has been waiting in the ready queue
Response time – amount of time it takes from when a request was submitted until the first response is produced, not output (for time-sharing environment)

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