Operating Sytem Lab Practicals

1. Course: Bachelor of Technology
Branch: Computer Science & Engineering
Semester: 6th
GURU JAMBHESHWAR UNIVERSITY OF
SCIENCE & TECHNOLOGY, HISAR
Submitted To: - Submitted By:-
Mr. Ajit Noonia Mukesh Kumar
Asstt. Professor in CSE Deptt. 1110751908
Department of Computer Science & Engineering
Prannath Parnami Institute of Management & Technology, Hisar
Prannath Parnami Universe, Website: ppu.edu.in

2. INDEX
Sr.
No.
Name of Experiment Date Remarks
1 Study of WINDOWS 2000 Operating System.
2 WAP simulate FCFS C.P.U. Scheduling
algorithm.
3 WAP to simulate SJF C.P.U. Scheduling
algorithm.
4 WAP simulate Priority C.P.U. Scheduling
algorithm
5 WAP simulate Round Robin C.P.U.
Scheduling algorithm.
6 WAP in C Banker’s algorithm for Deadlock
Avoidance.
7 WAP in C to implement FIFO page
replacement algorithm.
8 WAP in C to implement LRU page
replacement algorithm.

3. EXPERIMENT NO.=1
Aim:-- Study of WINDOWS 2000 Operating System.
Introduction to Window 2000:-
Windows 2000 is an operating system for use on both client and server computers. It was
produced by Microsoft and released to manufacturing on December 15, 1999 and launched to
retail on February 17, 2000. It is the successor to Windows NT 4.0, and is the last version of
Microsoft Windows to display the "Windows NT" designation. It is succeeded by Windows
XP (released in October 2001) and Windows Server 2003 (released in April 2003). During
development, Windows 2000 was known as Windows NT 5.0.
Four editions of Windows 2000 were released: Professional, Server, Advanced Server,
and Datacenter Server; the latter was both released to manufacturing and launched months
after the other editions. While each edition of Windows 2000 was targeted at a different
market, they shared a core set of features, including many system utilities such as
the Microsoft Management Console and standard system administration applications.
Support for people with disabilities was improved over Windows NT 4.0 with a number of
new assistive technologies and Microsoft increased support for different languages
and locale information.
All versions of the operating system support NTFS 3.0, Encrypting File System, as well as
basic and dynamic disk storage. The Windows 2000 Server family has additional features,
including the ability to provide Active Directory services (a hierarchical framework of
resources), Distributed File System (a file system that supports sharing of files) and fault-
redundant storage volumes. Windows 2000 can be installed through either a manual or
unattended installation. Unattended installations rely on the use of answer files to fill in
installation information, and can be performed through a bootable CD using
Microsoft Systems Management Server, by the System Preparation Tool.
Microsoft marketed Windows 2000 as the most secure Windows version ever at the time;
however, it became the target of a number of high-profile virus attacks such as Code
Red and Nimda. For ten years after its release, it continued to receive patches for security
vulnerabilities nearly every month until reaching the end of its lifecycle on July 13, 2010.
System Components:--
The architecture of Windows is a layered system of modules, as shown in Figure. The main
layers are the HAL, the kernel, and the executive, all of which run in protected mode, and a
large collection of subsystems that run in user mode. The user-mode subsystems are in two
categories. The environmental subsystems emulate different operating systems the protection
subsystems provide security functions. One of the chief advantages of this type.

4. Fig. Windows block diagram
16-Bit Windows Environment:--
The Win16 execution environment is provided by a VDM that incorporates additional
software, called Windows on Windows, that provides the Windows 3.1 kernel routines and
stub routines for window-manager and graphical device- interface (GDI) functions. The stub
routines call the appropriate Win32 subroutines—converting, or thunking, 16-bit addresses
into 32-bit ones. Applications that rely on the internal structure of the 16-bit window manager
or GDI may not work, because Windows on Windows does not really implement the 16-bit
API. Windows on Windows can multitask with other processes on Windows, but it resembles
Windows 3.1 in many ways. Only oneWin16 application can run at a time, all applications are
single threaded and reside in the same address space, and all share the same input queue.
These features imply that an application that stops receiving input will block all the other
Win16 applications, just a in Windows 3.x, and one Win16 application can crash other Win16
applications by corrupting the address space. Multiple Win16 environments can coexist,
however, by using the command start /separate win16application from the command line.

5. Win32 Environment:--
As mentioned earlier, the main subsystem in Windows is theWin32 subsystem. It runs Win32
applications and manages all keyboard, mouse, and screen I/O. Since it is the controlling
environment, it is designed to be extremely robust. Several features of Win32 contribute to
this robustness. Unlike processes in the Win16 environment, each Win32 process has its own
input queue. The window manager dispatches all input on the system to the appropriate
process’s input queue, so a failed process will not block input to other processes. The
Windows kernel also provides preemptive multitasking, which enables the user to terminate
applications that have failed or are no longer needed. In addition, Win32 validates all objects
before using them, to prevent crashes that could otherwise occur if an application tried to use
an invalid or wrong handle. The Win32 subsystem verifies the type of the object to which a
handle points before using that object. The reference counts kept by the object manager
prevent objects from being deleted while they are still being used and prevent their use after
they have been deleted.
Domains:--
Many networked environments have natural groups of users, such as students in a computer
laboratory at school or employees in one department in a business. Frequently, we want all the
members of the group to be able to access shared resources on their various computers in the
group. To manage the global access rights within such groups, Windows uses the concept of a
domain. Previously, these domains had no relationship whatsoever to the domain name system
(DNS) that maps Internet host names to IP addresses; now, however, they are closely related.
Specifically, a Windows domain is a group of Windows workstations and servers that share a
common security policy and user database. Since Windows now uses the Kerberos protocol for
trust and authentication, a Windows domain is the same thing as a Kerberos realm. Previous
versions of NT used the idea of primary and backup domain controllers; now all servers in a
domain are domain controllers. In addition, previous versions required the setup of one way
trusts between domains. Windows uses a hierarchical approach based on DNS and allows
transitive trusts that can flow up and down the hierarchy. This approach reduces the number of
trusts required for n domains from n ∗ (n−1) to O(n). The workstations in the domain trust the
domain controller to give correct information about the access rights of each user (via the user’s
access token). All users retain the ability to restrict access to their own work stations, no matter
what any domain controller may say. Because a business may have many departments and a
school may have many classes, it is often necessary to manage multiple domains within a
single organization. A domain tree is a contiguous DNS naming hierarchy for managing
multiple domains. For example, bell-labs.com might be the root of the tree, with research.bell-
labs.com and pez.bell-labs.com as children—domains research and pez. A forest is a set of
noncontiguous names. An example would be the trees bell-labs.com and/or lucent.com. A forest
may be made up of only one domain tree, however. Trust relationships can be set up between
domains in three ways: one-way, transitive, and cross-link. Versions of NT through Version 4.0
allowed only
one-way trusts to be set up. A one- way trust is exactly what its name implies: Domain A is told
it can trust domain B. However, B will not trust A unless another relationship is configured.
Under a transitive trust, if A trusts B and B trusts C, then A, B, and C all trust one another,
since transitive trusts are two-way by default. Transitive trusts are enabled by default for new
domains in a tree and can be configured only among domains within a forest. The third type, a

6. cross-link trust, is useful to cut down on authentication traffic. Suppose that domains A and B
are leaf nodes and that users in A often use resources in B. If a standard transitive trust is used,
authentication requests must traverse up to the common ancestor of the two leaf nodes; but if A
and B have a cross linking trust established, the authentications can be sent directly to the other
node.
System Administrator of Window 2000:--
Features of Window 2000:--

7. Features Functions Benefits
Greater system stability
Improved hardware
support
 Supports AGP, DVD,
USB, IEEE 1394.
 Improved DirectX®
and DirectSound®
support.
Computers are more compatible and more
stable than with previous Microsoft®
operating systems. This is due in part to
fewer driver conflicts and increased ease of
setup.
Improved program
support
 Microsoft claims 600
new programs tested as
being compatible.
 Improved productivity, through ability
to use a wider variety of programs.
 Less downtime spent troubleshooting
technical issues associated with
program incompatibility.
New Microsoft®
Windows® Installer
 Provides a standard
format for program
setup, including
installation and repair.
 Tracks key files and
automatically replaces
or repairs damaged
files.
 Helps to provide more reliable
programs.
 Contributes to efficiency in systems
management.
 Helps prevent DLL conflicts.
Auto restart of failed
services
 Automatically caches
data in progress.
 Better retention of data.
 Less downtime.
 Improved stability.

8. Increased manageability
Active
directory
 Dynamic linking of
system, user, and
enterprise information.
 For the system administrator, simplified
system and asset administration over the
network.
 For the user, easier access to shared
network devices.
IntelliMirror®  Duplicates user profiles
and data, including
security permissions,
directory accesses, and
local computer data and
programs onto the
server.
 Faster installation of new computers.
 Protection from data loss.
 Group setup of security and access levels.
 Easier administration of portable
computers.
 Better support of roaming users.
 Easier replacement of failed computers —
reduces downtime.
 Easier administration of corporate
standards.
 Distribution of software upgrades without a
service call; provides unattended
installation procedures.
ACPI  Manages system,
device, processor
power, battery, and
system events.
 Provides instant on,
instant off power.
 Offers power-saving
features.
 Provides Wake up on
LAN feature.
 Power savings equate to lower electricity
bills.
 Remote systems management through
Wake up on LAN.
 Improved mobile power management.
Web Based
Enterprise
Management
(WBEM)
 Support for Internet
protocol standards.
 Allows IT managers to manage their
environments from anywhere with Web
access.
 Allows easier management of remote
computers.

9. Increased performance
Optimized for
Pentium® II
processors
and above.
 Takes advantage of the latest
advances in Intel® processing
technologies.
 According to Microsoft, greater
computer performance over
Windows 95.
 Higher program performance.
Enhanced
search for
files or
folders
 Automatically lists recent network
locations visited and allows user to
search multiple network resources
and recently visited Internet
resources simultaneously.
 Makes searching for
information more automated.
Greater system security
Encrypted
File System
with NTFS
5.0
 Ability to encrypt data to the local
hard disk.
 Applies additional security
permissions to the hard disk and
uses the Encrypting File System
(EFS) to protect sensitive
information.
 Protects hard disk data even if
the hard disk is physically
removed from the computer.
Public key
support
 Allows digital signatures for
programs, drivers, and computers.
 Verifies authenticity of
components.
 Allows users to set up secure
network communications over a
public network.
 Authenticates e-mail source.
Internet
Protocol
Security
(IPSec)
 Encrypts of data above the
network layer.
 Helps protect against
unauthorized users obtaining
information over the Internet
through the World Wide Web
and maintains confidentiality.
Greater Web-browsing experience
Internet
Explorer 5.0
 According to Microsoft, offers a
20 percent increase in the speed of
Web page loading.
 Improves the organization of
Favorites.
 Increased productivity.
 Greater flexibility in organizing
URLs.

10. Experiment No.=2
Aim:-- WAP simulate FCFS C.P.U. Scheduling algorithm.
#include<stdio.h>
#include<conio.h>
void main()
{
char pn[10] [10];
int arr[10],bur[10],star[10],finish[10],tat[10],wt[10],i,n;
int totwt=0, tottat=0;
clrscr();
printf("enter the no of process ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("enter the process name, arrival time & burst time");
scanf("%s%d%d",&pn[i], &arr[i], &bur[i]);
}
for(i=0;i<n;i++)
{
if(i==0)
{
star[i]=arr[i];
wt[i]=star[i]-arr[i];
finish[i]=star[i]+bur[i];
tat[i]=finish[i]-arr[i];
}
else
{
star[i]=finish[i-1];
wt[i]=star[i]-arr[i];
finish[i]=star[i]+bur[i];
tat[i]=finish[i]-arr[i];
}}
printf("n pname arrtime burtime start tat finish");
for(i=0;i<n;i++)
{
printf("n %s %6d % 6d%6d%6d%6d" ,pn[i],arr[i],bur[i],star[i],tat[i],finish[i]);
totwt +=wt[i];
tottat+=tat[i];
}
printf("n average waiting time: %f",(float) totwt/n);
printf("n average turn around time: %f",(float) totwt/n);
getch();
}
Output:--

11. Experiment No.=3

12. Aim:-- WAP to simulate SJF C.P.U. Scheduling algorithm.
#include<stdio.h>
#include<conio.h>
void main()
{
int i,j,n,brust_time[10],start_time[10],end_time[10],wait_time[10],temp,tot;
float avg;
clrscr();
printf("Enter the No. of jobs:");
scanf("%d",&n);
for(i=1;i<=n;i++)
{
printf("Enter %d process burst time:",i);
scanf("%d",&brust_time[i]);
}
for(i=1;i<=n;i++)
{
for(j=i+1;j<=n;j++)
{
if(brust_time[i]>brust_time[j])
{
temp=brust_time[i];
brust_time[i]=brust_time[j];
brust_time[j]=temp;
}
}
if(i==1)
{
start_time[1]=0;
end_time[1]=brust_time[1];
wait_time[1]=0;
}
else
{
start_time[i]=end_time[i-1];
end_time[i]=start_time[i]+brust_time[i];
wait_time[i]=start_time[i];
}
}
printf("nn BURST TIME t STARTING TIME t END TIME t WAIT TIMEn");
printf("n ********************************************************n");
for(i=1;i<=n;i++)

13. {
printf("n %5d %15d %15d %15d",brust_time[i],start_time[i],end_time[i],wait_time[i]);
}
printf("n ********************************************************");
for(i=1,tot=0;i<=n;i++)
tot+=wait_time[i];
avg=(float)tot/n;
printf("n AVERAGE WAITING TIME=%f",avg);
for(i=1,tot=0;i<=n;i++)
tot+=end_time[i];
avg=(float)tot/n;
printf("nn AVERAGE TURNAROUND TIME=%f",avg);
for(i=1,tot=0;i<=n;i++)
tot+=start_time[i];
avg=(float)tot/n;
printf("nn AVERAGE RESPONSE TIME=%fnn",avg);
getch();
}
Output:--

14. Experiment No.=4
Aim:-- WAP simulate Priority C.P.U. Scheduling algorithm.
#include<stdio.h>
#include<conio.h>
int main()

15. {
int i,j,n,time,sum_wait=0,sum_turnaround=0;
int smallest,at[10],bt[10],priority[10],remain;
printf("Enter no of Processes : ");
scanf("%d",&n);
clrscr();
remain=n;
for(i=0;i<n;i++)
{
printf("Enter arrival time, burst time and priority for process p%d :",i+1);
scanf("%d",&at[i]);
scanf("%d",&bt[i]);
scanf("%d",&priority[i]);
}
priority[9]=11;
printf("nnProcesst|Turnaround time|waiting timen");
for(time=0;remain!=0;)
{
smallest=9;
for(i=0;i<n;i++)
{
if(at[i]<=time && priority[i]<priority[smallest] && bt[i]>0)
{
smallest=i;
}}
time+=bt[smallest];
remain--;
printf("P[%d]t|t%dt|t%dn",smallest+1,time-at[smallest],time-at[smallest]-bt[smallest]);
sum_wait+=time-at[smallest]-bt[smallest];
sum_turnaround+=time-at[smallest];
bt[smallest]=0;
}
printf("nAvg waiting time = %fn",sum_wait*1.0/n);
printf("Avg turnaround time = %f",sum_turnaround*1.0/n);
return 0;
}
Output:--

16. Experiment No.=5
Aim:-- WAP simulate Round Robin C.P.U. Scheduling algorithm.

17. #include<stdio.h>
#include<conio.h>
int main()
{
int i,j,n,time,remain,flag=0,ts;
int sum_wait=0,sum_turnaround=0,at[10],bt[10],rt[10];
printf("Enter no of Processes : ");
scanf("%d",&n);
clrscr();
remain=n;
for(i=0;i<n;i++){
printf("Enter arrival time and burst time for Process P%d :",i+1);
scanf("%d",&at[i]);
scanf("%d",&bt[i]);
rt[i]=bt[i];
}
printf("Enter time slice");
scanf("%d",&ts);
printf("nnProcesst|Turnaround time|waiting timenn");
for(time=0,i=0;remain!=0;)
{
if(rt[i]<=ts && rt[i]>0){
time+=rt[i];
rt[i]=0;
flag=1;
}
else if(rt[i]>0){
rt[i]-=ts;
time+=ts;
}
if(rt[i]==0 && flag==1)
{
remain--;
printf("P[%d]t|t%dt|t%dn",i+1,time-at[i],time-at[i]-bt[i]);
sum_wait+=time-at[i]-bt[i];
sum_turnaround+=time-at[i];
flag=0;
}if(i==n-1)
i=0;
else if(at[i+1]<=time)
i++;
}
printf("nAvg sum_wait = %fn",sum_wait*1.0/n);
printf("Avg sum_turnaround = %f",sum_turnaround*1.0/n);
return 0;
}
Output:--

18. Experiment No.=6
Aim:-- WAP in C Banker’s algorithm for Deadlock Avoidance.

19. #include<stdio.h>
#include<conio.h>
int max[100][100];
int alloc[100][100];
int need[100][100];
int avail[100];
int n,r;
void input();
void show();
void cal();
int main()
{
int i,j;
printf("********** Baner's Algo ************n");
input();
show();
cal();
getch();
return 0;
}
void input()
{
int i,j;
printf("Enter the no of Processest");
scanf("%d",&n);
printf("Enter the no of resources instancest");
scanf("%d",&r);
printf("Enter the Max Matrixn");
for(i=0;i<n;i++)
{
for(j=0;j<r;j++)
{
scanf("%d",&max[i][j]);
}}
printf("Enter the Allocation Matrixn");
for(i=0;i<n;i++)
{
for(j=0;j<r;j++)
{
scanf("%d",&alloc[i][j]);
}}
printf("Enter the available Resourcesn");
for(j=0;j<r;j++)

20. {
scanf("%d",&avail[j]);
}}
void show()
{
int i,j;
printf("Processt Allocationt Maxt Availablet");
for(i=0;i<n;i++)
{
printf("nP%dt ",i+1);
for(j=0;j<r;j++)
{
printf("%d ",alloc[i][j]);
}
printf("t");
for(j=0;j<r;j++)
{
printf("%d ",max[i][j]);
}
printf("t");
if(i==0) {
for(j=0;j<r;j++)
printf("%d ",avail[j]);
}}}
void cal() {
int finish[100],temp,need[100][100],flag=1,k,c1=0;
int safe[100];
int i,j;
for(i=0;i<n;i++)
{
finish[i]=0;
}
for(i=0;i<n;i++)
{
for(j=0;j<r;j++)
{
need[i][j]=max[i][j]-alloc[i][j];
}}
printf("n");
while(flag) {
flag=0;
for(i=0;i<n;i++)
{

21. int c=0;
for(j=0;j<r;j++)
{
if((finish[i]==0)&&(need[i][j]<=avail[j]))
{
c++;
if(c==r) {
for(k=0;k<r;k++)
{
avail[k]+=alloc[i][j];
finish[i]=1;
flag=1;
}
printf("P%d->",i);
if(finish[i]==1)
{
i=n;
}}}}}}
for(i=0;i<n;i++)
{
if(finish[i]==1) {
c1++;
}
else
{
printf("P%d->",i);
}}
if(c1==n) {
printf("n The system is in safe state");
}
else
{
printf("n Process are in dead lock");
printf("n System is in unsafe state");
}
}
Output:--

22. Experiment No.=7
Aim:-- WAP in C to implement FIFO page replacement algorithm.
#include<stdio.h>

23. #include<conio.h>
int main()
{
int i,j,n,a[50],frame[10],no,k,avail,count=0;
clrscr();
printf("ENTER THE NUMBER OF PAGES:");
scanf("%d",&n);
printf("n ENTER THE PAGE NUMBER :");
for(i=1;i<=n;i++)
scanf("%d",&a[i]);
printf("n ENTER THE NUMBER OF FRAMES :");
scanf("%d",&no);
for(i=0;i<no;i++)
frame[i]= -1;
j=0;
printf("tref stringt page framesn");
for(i=1;i<=n;i++)
{
printf("%dtt",a[i]);
avail=0;
for(k=0;k<no;k++)
if(frame[k]==a[i])
avail=1;
if (avail==0)
{
frame[j]=a[i];
j=(j+1)%no;
count++;
for(k=0;k<no;k++)
printf("%dt",frame[k]);
}
printf("n");
}
printf("Page Fault Is %d",count);
getch();
return 0;
}
Output:--

24. Experiment No.=8
Aim:-- WAP in C to implement LRU page replacement algorithm.

25. #include<stdio.h>
#include<conio.h>
main()
{
int q[20],p[50],c=0,c1,d,f,i,j,k=0,n,r,t,b[20],c2[20];
clrscr();
printf("Enter no of pages:");
scanf("%d",&n);
printf("Enter the reference string:");
for(i=0;i<n;i++)
scanf("%d",&p[i]);
printf("Enter no of frames:");
scanf("%d",&f);
q[k]=p[k];
printf("nt%dn",q[k]);
c++;
k++;
for(i=1;i<n;i++)
{
c1=0;
for(j=0;j<f;j++)
{
if(p[i]!=q[j])
c1++;
}
if(c1==f)
{
c++;
if(k<f)
{
q[k]=p[i];
k++;
for(j=0;j<k;j++)
printf("t%d",q[j]);
printf("n");
}
else
{
for(r=0;r<f;r++)
{
c2[r]=0;
for(j=i-1;j<n;j--)
{
if(q[r]!=p[j])

26. c2[r]++;
else
break;
}
}
for(r=0;r<f;r++)
b[r]=c2[r];
for(r=0;r<f;r++)
{
for(j=r;j<f;j++)
{
if(b[r]<b[j])
{
t=b[r];
b[r]=b[j];
b[j]=t;
}
}
}
for(r=0;r<f;r++)
{
if(c2[r]==b[0])
q[r]=p[i];
printf("t%d",q[r]);
}
printf("n");
}
}
}
printf("nThe no of page faults is %d",c);
getch();
return 0;
}
Output:--