Set - 5

Question 11 :

How the Kernel handles both the page stealer and the fault handler?

Answer :

The page stealer and the fault handler thrash because of the shortage of the memory. If the sum of the working sets of all processes is greater that the physical memory then the fault handler will usually sleep because it cannot allocate pages for a process. This results in the reduction of the system throughput because Kernel spends too much time in overhead, rearranging the memory in the frantic pace.


Question 12 :

Explain different types of Unix systems.

Answer :

The most widely used are: 1. System V (AT&T) 2. AIX (IBM) 3. BSD (Berkeley) 4. Solaris (Sun) 5. Xenix ( A PC version of Unix)


Question 13 :

Explain kernal and shell.

Answer :

Kernal: It carries out basic operating system functions such as allocating memory, accessing files and handling communications. Shell:A shell provides the user interface to the kernal.There are 3 major shells : C-shell, Bourne shell , Korn shell


Question 14 :

What is ex and vi ?

Answer :

ex is Unix line editor and vi is the standard Unix screen editor.


Question 15 :

Which are typical system directories below the root directory?

Answer :

(1)/bin: contains many programs which will be executed by users
(2)/etc : files used by administrator
(3)/dev: hardware devices
(4)/lib: system libraries
(5)/usr: application software
(6)/home: home directories for different systems.