Operating System

This document provides information about various aspects of operating system including OS initiation, memory compaction, state transition, GUI vs CLI, time slicing, seek strategies, peripheral device communication, file systems, Android source code access, and UNIX commands.

Operating System
Table of Contents

Introduction......................................................................................................................................1
Question 1. Explicate sequence of steps that are being taken via OS initiation for execution of
their application......................................................................................................................1
Question 2. Carry out memory compaction and illustrate memory allocation.......................1
Question 3. Draw diagram for state transition that explicate distinct kind of interrupts while
process transition....................................................................................................................2
Question 4. Comparison as well as contrast among GUI and CLI. Illustrate advantages and
characteristics of GUI.............................................................................................................3
Question 5. Explicate time slicing within round robin algorithm that creates impact on overall
performance of operating system...........................................................................................4
Question 6...............................................................................................................................5
Draw arm movement for seek strategies along with track time.............................................5
Question 7. How peripheral devices communicate with the operating system for furnishing
input and output......................................................................................................................7
Question 8. Explore three file system within current OS.......................................................7
Question 9. Specify the extent up to which android source code can be accessed via public
and explicate whether it should be more open system...........................................................8
Question 10. Illustrate different UNIX commands................................................................8
References......................................................................................................................................11

Introduction
The software that acts like interface among computer hardware components along with
their user is referred to as operating system. This aids within carrying out interaction with
computer without having knowledge about language of the computer (Anwar and et. al, 2016). It
is program that is initially loaded within the computer via boot program as well as management
of application program within the system. The report will provide different aspects related with
operating system.
Question 1. Explicate sequence of steps that are being taken via OS initiation for execution of
their application
The operating system is accountable for recognition of mouse event. This routes event to
program that is under the cursor and it is windows explorer which determines entities that are
under the cursor as well as perform relevant actions on this. For an instance if entity is desktop
file, then the default actions will be determined for this. In case, if this is file then ShellExecute
will be called that will further look via registry for identification of file class dependent on
extension via utilisation of data from the HKEY_CLASSES_ROOT. If file was identified then
operation system will start other processes by making use of file like a parameter for it. Mouse
events will be routed for the application.
The processor is accountable for recognising the screen-tap or mouse click. It gets
positioning of cursor and enables to look what program launcher is waiting for to be clicked. It
will implement program launcher that runs the program.
Question 2. Carry out memory compaction and illustrate memory allocation
Memory compaction refers to the process that is associated with moving allocated objects
together as well as leaves empty spaces together. This implies the process where free space will
be gathered within the larger memory chunk for making certain space available for distinct
processes. This is also referred to as swapping. It denotes the process which can be temporarily
swapped out of the main memory into the disk or secondary storage that will make memory
available for other processes (Dronamraju and et. al, 2020). After certain instance of time, the
system will swap back processes into the main memory from secondary. The performance gets
impacted via process of swapping but this will aid within execution of multiple as well as big
processes within parallel. The example of memory compaction is illustrated below:

0 OS
400K P1
700K P2
1100K 400 K
1300K P3
1600K 300 K
2000K P4
2200K 200 K
The above figure illustrates the exact memory allocations which clearly specify that
certain memory is lost in between the processes which can be utilised within other processes.
0 OS
400K P1
700K P2
1100K P3
1300K P4
900 K
The figure shows memory compaction where the unallocated memory is gathered in one
place that can be used within other processes as per the requests that are being made.
Question 3. Draw diagram for state transition that explicate distinct kind of interrupts while
process transition
The process that are being implemented via the process comprises of distinct states, they
are also referred to as status of the process. Process state refers to the state field within the
process descriptor. Processes might occupy wide varieties of states. The process from their
creation to completion passes via different states (Min and et. al, 2018). The process state is
accountable for describing static view of the processes but they move continuously among
different states as per well-defined rules. The different transition states are specified beneath:

 Create (New): In this stage process will be created but it not done yet. This denotes
program that is present within the secondary memory that might be picked by operating
system for creation of the process. Ready: After creating process, this enters within ready state that is loaded within the
main memory. Now the process within is ready for execution as well as is in waiting state
for getting CPU for execution.
Illustration 1: State Transition Diagram Run: The process is chosen via a CPU for implementation along with instructions that
are associated with the process. They are further implemented via a CPU cores that are
being available (Oldcorn and Paltashev, 2017). Wait or blocked: When process requests for accessing needs or I/O via user then they
have to access critical regions that they enter within wait or blocked state. The process
will further wait within the memory as well as do not need any CPU and main memory.
When I/O operations will be completed then process will enter within ready state. Completed or terminated: The process will be killed Suspend ready: This implies that process was within ready state state but are swapped
out from the main memory and are further placed within the external storage via

scheduler is referred to as ready state. Furthermore, processes will be in transit back to
the ready state when process will be brought within the main memory.
 Suspend blocked or suspend wait: This will be utilising process that will perform I/O
operation as well as lack main memory that is being caused via them for moving into
secondary memory.
Question 4. Comparison as well as contrast among GUI and CLI. Illustrate advantages and
characteristics of GUI
User interface implies term that is utilised for specification of manner in which user
interacts with computer or any other electronic device. GUI (graphical user interface) allows
individuals to communicate with system with utilisation of components like icons, windows, text
boxes, radio buttons and labels. This is easy for performing tasks with the use of GUI as this do
not involve learning commands. Along with CLI (command land interface) is also referred to as
console or character user interface which enables user within entering commands in the terminal
for performing distinct tasks (Seo and Lee, 2017). The contrast and comparison is illustrated
beneath:
Basis CLI GUI
Basic This is accountable for enabling
users for interacting with system
via commands
The graphical user interface permits
users or individuals for interacting
with system by utilisation of
graphics that comprises of icons,
images, etc.
Device utilised Generally keyboard Keyboard and mouse is used
Ease for carrying out
task
This becomes hard for carrying
out operation and acquire relevant
levels of expertise
It is easy to carry out distinct tasks
that do not need any kind of
expertise.
Precision, flexibility
and appearance
High precision is being offered but
flexibility is intrasigent. Further
appearance cannot be altered.
In this case precision is low but
renders more flexibility. Users can
make custom alterations as per the
requirements.

Extensibility and
integration
There lies extensive scope for
making relevant improvisations
Restricted modifications can be
made.
The similarity that prevails among both the terms i.e. CLI and GUI is that both provides
the user with relevant controls for accessing the system in different manner.
Question 5. Explicate time slicing within round robin algorithm that creates impact on overall
performance of operating system
The round robin implies pre-emptive algorithm where CPU will shift to next process after
determinate frame of time that is referred to as time slice/time quantum. The process which will
be pre-empted will be added at end of queue. Time slice refers to assigning significant time to
each process. In this case, when this consumes the timeslice where the thread will be kept at end
of their queue within the ready queue as well as the next READY thread at same priorities level
is furnished control (Silberschatz, Galvin and Gagne, 2014). This factor or value needs to be
minimum that will be further assigned to peculiar task that must be processed but this might vary
depending on the kind of operating system that is being used.
With the usage of time slice the performance will be improvised as each job will have fair
allocation of the CPU along with this each process is handled without any kind of priorities.
When process will be implemented for peculiar frame of time then process will be preempted as
well as other process will be executed for the given frame. This means that performance will be
better as each activity will be allotted certain frame of time where they can execute.
Question 6.
Draw arm movement for seek strategies along with track time
The track requests are:
17 34 1 26 3 12 19 61 23
As per the given details the head starts at the track = 40.
First Come first serve: This is simplest disk scheduling algorithm which is accountable for
addressing request in the manner they arrive within the queue. Here, each request is provided
with fair chance through which they are being addressed but the seek time is not optimised.

The total track is 217.
SSTF (Shortest Seek Time First): In this case, the requests that possess shortest seek
time will be executed first. Thus, it becomes important to calculate the seek time of each in
advance within the queue and accordingly schedule the associated seek time (Smith, 2020). This
means that the request that is near to dusk arm has to be implemented first.

In this case, the total seek time or track travelled are 81.
LOOK: Here, the request arm goes to last request that has been made and this will be
serviced in front of the head. Further, it will reverse the direction from there. This leads to
prevention of extra delay that has taken place because of unnecessary traversal.
The total track that is travelled is 81.
Question 7. How peripheral devices communicate with the operating system for furnishing input
and output.
Peripheral devices are utilised for processing or storing instructions for delivering
processed data within the computer. These devices are accountable for rendering input-output
functionalities for a system that serves like auxiliary device. They are further segregated into
three, they are: input, output and storage devices. Here, input device is accountable for
converting incoming instructions along with data within different patterns that involves electrical
signals within the binary code that are further comprehensible for digital computers (Tarazi and
et. al, 2016). Here, the output device is accountable for reversing processes that are accountable
for translation of digitalised signals within intelligible form for their users.
Question 8. Explore three file system within current OS.
File system refers to method that involves organising files on the physical media like
hard disks, flash drives and CD's. Here, users are presented with ample of choices for file system
while formatting media and they are dependent on kind of media that is involved along with

situations where media is generally formatted. The three commonly file systems that are used
within windows are illustrated below: New technology file system (NTFS): It is a well-formed and modern file system that is
utilised by Windows 7, 8 and Vista. This furnishes relevant volumes of the information
that comprises of extending partitions to 16 million TB, files that are being stored can be
of the size of partition and they generally become fragmented but must be defragmented
after one or more months. FAT file system: It is a general purpose file system which is compatible with operating
system like (Mac OSX, Windows and Unix/Linux) that comprises of simple technical
underpinnings. The certain aspects associated with FAT file system includes: can be
extended up to 2TB and partitions cannot be greater than 32GB. They are utilised with
the devices that have smaller capacity. HFS Plus file system: It denotes Hierarchical file system that is being given via Apple
for dealing with Mac OSX. The volume that is being provided via 8 million TB, files
stored within this can be as large as partition itself and users of Window will only be
able to read but not write (Yang and Cheng, 2020). This is accountable for enhancing
maximum files and this also illustrates significant number of allocation blocks that are
present on the disk as well as minimise the size of file. This further leads to optimisation
of storage capacity of larger hard disk.
Question 9. Specify the extent up to which android source code can be accessed via public and
explicate whether it should be more open system.
Google has acquired Android.inc in 2005 and they started it as open source android
project that is open to the people. It is open source but the latest version that is Android 11 is not
available for the developers for downloading. The last version that can be downloaded is
Android Ice Cream Sandwich (4.14). In case if android would be completely open source then it
would be easy for having enhanced memory management as well as integrated system that will
enable different developers to make alterations within the latest version accordingly.
Question 10. Illustrate different UNIX commands
Chmod: This command is utilised for changing the access mode for the file. The syntax
for this is specified beneath:
Chmod [reference] [operator] [mode] file....

Reference: They are utilised for distinguishing users for whom permissions are applied
that is they implies list of letters that illustrates to whom the permissions must be delivered. The
references are specified by one or more letters, they are:
Reference Class Description
U Owner File’s owner
G Group Users are members that belong to
file’s group
O Others Users are not the owner
A All All three, same as ugo
Examples: $ chmod a-x sample.txt (this will deny all the execute permissions that are being
given to all)
$ chmod go+rw sample.txt (this will change the permission of file to readable
along with writable by others and groups)
grep: It is liable for searching specific patterns of the character as well as display all the
linesthat comprises of those pattern. In this case, the pattern that will be searched within the file
is defined as regular expression. The term grep stands for globally search for regular expression
and print out.
Syntax: grep [options] pattern [files]
The different options that are available with user in this context are specified beneath:
Options Description
-c Count of the line will only specified
-h Display matched line but filenames will not be displayed
-i Ignore cases for the matching
-l Display filename only
-n Illustrate matched lines along with line numbers
-v All the lines will be illustrated that do not match pattern
-w Match the entire word

Examples: $grep –c “linux” sample.txt (find number of lines that will match string
“linux” within the given pattern).
$grep –l “linux” * (find all the files that comprises of pattern or
string)
Ls: It is accountable for listing files as well as directories that are present within the file
system as well as illustrate detailed information related with them. This acts as GNU core utility
package that is installed within the linux distribution.
Syntax: ls [options] [files]
Examples: ls –l (illustrate all the information about the directories or files)
Ls –lh (display the size of file in read format that is MB, KB, etc.)
mkdir: This command enables Linux users to formulate directories. It is utilised for
creation of multiple directories and set permissions for the same.
Syntax: mkdir [options] [directories]
Examples: mkdir –m777 DirM (all the users can be given permissions and for this –m
option must be added along with 777 for creating directory)
mkdir {dir1,dir2,dir3,dir4} (for creating multiple directories within the
current location and spaces must not be used within)

References
Books & Journals
Anwar, F. and et. al, 2016, November. Timeline: An operating system abstraction for time-aware
applications. In 2016 IEEE Real-Time Systems Symposium (RTSS) (pp. 191-202). IEEE.
Dronamraju, R. and et. al, NetApp Inc, 2020. Methods for minimizing fragmentation in ssd
within a storage system and devices thereof. U.S. Patent Application 16/584,025.
Min, C. and et. al, 2018, April. Solros: a data-centric operating system architecture for
heterogeneous computing. In Proceedings of the Thirteenth EuroSys Conference (pp. 1-
15).
Oldcorn, D. and Paltashev, T.T., Advanced Micro Devices Inc, 2017. Memory management with
reduced fragmentation. U.S. Patent Application 15/094,171.
Seo, D., and Lee, K. 2017. Comparing security vulnerability by operating system
environment. International Journal of Services Technology and Management, 23(1-2),
154-164.
Silberschatz, A., Galvin, P.B. and Gagne, G., 2014. Operating system concepts essentials (pp. I-
XX). Hoboken: Wiley.
Smith, S. 2020. Linux Operating System Services. In Programming with 64-Bit ARM Assembly
Language (pp. 161-176). Apress, Berkeley, CA.
Tarazi, C. and et. al, 2016. Operating System Security using SNMP.
Yang, D. and Cheng, D., 2020, June. Efficient gpu memory management for nonlinear dnns.
In Proceedings of the 29th International Symposium on High-Performance Parallel and
Distributed Computing (pp. 185-196).
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