a2zinterviews

11.	What is called a page fault?
	Page fault is referred to the situation when the process addresses a page in the working set of the process but the process fails to locate the page in the working set. And on a page fault the kernel updates the working set by reading the page from the secondary device.

12.	What do you mean by u-area (user area)?
	This contains the private data that is manipulated only by the Kernel. This is local to the Process, i.e. each process is allocated a u–area

13.	What are the different types of buffering is supported by UNIX?
	Fuly buffered Line buffered Un buffered

14.	What is the purpose of exec functions?
	When a process calls one of the exec functions that process is completely replaced by the new program. The new program stats execution from main function. The processed does not change across an exec because a new process is not created.But this function replaces the current process with new program from disk.

15.	Define process group?
	A process group is a collection of one or more processes. Each process group has a unique process ID. A function getpgrp returns the process group id of the calling process.