OSA

1. OS and Applications
R.Vijay

2. Describe the different types of network file
sharing protocol with OS (Operating System)
comparison

3. OS and File Sharing Protocol
20XX presentation title 3
SMB (Server Message Block):
Description: SMB is a network file sharing protocol that allows communication
between devices for sharing files, printers, and other resources. It operates over
the TCP/IP protocol.
OS Compatibility: Primarily used in Windows environments. Also supported by
Linux and macOS through Samba.
CIFS (Common Internet File System):
Description: CIFS is an enhanced version of SMB, developed to address some
limitations of the original SMB protocol. It includes additional features.
OS Compatibility: CIFS is essentially an extension of SMB and is compatible with
Windows, Linux, and macOS through tools like Samba.

4. 20XX presentation title 4
Comparison:
Windows Compatibility: SMB and CIFS are native to Windows, providing seamless integration. NFS is well-
supported in Unix/Linux environments.
Cross-Platform Support: SMB, CIFS, NFS, and FTP offer cross-platform compatibility, allowing file sharing
between Windows, Linux, and macOS systems.
Security: SCP, SFTP, and WebDAV provide secure file transfer options with encryption, making them
suitable for sensitive data.
Ease of Use: SMB and CIFS are generally easier to set up in Windows environments. FTP and WebDAV
are widely accessible but may require additional configurations.
Performance: Performance may vary based on the specific implementation, but generally, protocols like
SMB, CIFS, and NFS offer good performance.
Choosing the Right Protocol:
Windows-Centric Environment: SMB or CIFS.
Mixed Environment: SMB/CIFS with Samba for Linux and macOS, or NFS for Unix/Linux environments.
Secure File Transfer: SCP, SFTP, or WebDAV with encryption.

5. 20XX presentation title 5
Suggested Protocol for ABC Web Solutions:
Considering that ABC Web Solutions has a diverse environment with branches in Colombo, Kandy, and
Jaffna, and different departments, including Marketing & Consultation, Development, Finance,
Procurement/HR, Maintenance, and IT, a protocol that supports cross-platform compatibility would be
ideal. In this case, SMB/CIFS is a suitable choice.
Advantages:
Well-supported in Windows environments.
Compatible with Linux and macOS through Samba.
Can be configured for secure file sharing.
Provides features like authentication and access control.
Implementation:
Implement SMB/CIFS shares for file sharing within the organization.
Use Samba for Linux and macOS systems to seamlessly integrate with the Windows-centric
environment.
By implementing SMB/CIFS, ABC Web Solutions can achieve a unified file sharing solution that caters
to the needs of its diverse operating environment, ensuring smooth collaboration and data exchange
across different departments and branches.

6. 20XX presentation title 6
You have been provided 500 GB of Disk space of Server with
8GB of RAM, describe the partition types and capacity you will
configure for this Linux server

7. 20XX presentation title 7
The partitioning scheme for a Linux server depends on various factors, including the server's
purpose, the type of applications it will host, and the desired level of system security. Here is a
suggested partitioning scheme based on the given resources (500 GB disk space and 8 GB of RAM):
Root Partition (/):
Capacity: 20-30 GB
Description: The root partition contains the operating system files and system binaries. Allocating a
sufficient but not overly large space ensures the core system files have ample room to operate.
Swap Partition:
Capacity: 16 GB (equal to or slightly larger than RAM)
Description: The swap partition is used as virtual memory when the physical RAM is fully utilized. For
a server with 8 GB of RAM, a swap partition of 16 GB is a common recommendation to handle
potential memory overflows.
/var Partition:

8. Capacity: 50 GB
Description: The /var directory stores variable data, such as logs, databases, and cached files.
Allocating a significant amount of space for /var helps ensure that logs and other variable data do not
fill up the root partition.
/home Partition:
Capacity: Remaining space (approximately 400 GB)
Description: The /home directory typically holds user data and home directories. Allocating the
remaining disk space to /home ensures sufficient storage for user files and data.
/tmp Partition:
Capacity: 10-20 GB
Description: The /tmp directory stores temporary files. Allocating a separate partition for /tmp can
help prevent the system from becoming unresponsive due to excessive temporary file creation.
/usr Partition:
Capacity: 30-40 GB
Description: The /usr directory contains user-related programs, libraries, and documentation.
Allocating a reasonable amount of space for /usr ensures that there is room for additional software
installations.

9. 20XX presentation title 9
/opt Partition:
Capacity: 20 GB
Description: The /opt directory is used for optional or additional software packages.
Allocating space for /opt provides room for installing third-party software or applications.
This partitioning scheme is a general recommendation, and you may need to adjust the
sizes based on your specific requirements and usage patterns. Additionally, the scheme
assumes a single-disk setup; if you have multiple disks, you might want to consider RAID
configurations for redundancy and performance improvement. Always ensure that you have
proper backups before making significant changes to disk partitions.

10. Discuss the suitable solution to provide security in the head office network,
describe with a Diagram (features:- Internet Filter-Proxy & Network Filter)

11. internet Filter-Proxy:
Description: An internet filter-proxy acts as an intermediary between users and the internet,
intercepting and filtering web requests. It helps control and monitor internet access, block
malicious content, and enhance overall network security.
Features:
Content Filtering: Blocks access to malicious websites, inappropriate content, and other
potential security risks.
Bandwidth Control: Manages and optimizes bandwidth usage, preventing abuse and
ensuring fair distribution.
Anonymity Control: Controls access to anonymizing proxies, enhancing user accountability.
Logging and Reporting: Records user activities for auditing purposes and generates reports
on internet usage.

12. Network Filter:
Description: A network filter, also known as a firewall, monitors and controls incoming and
outgoing network traffic based on predetermined security rules. It serves as a barrier
between the internal network and the external world, protecting against unauthorized access
and potential cyber threats.
Features:
Packet Filtering: Examines packets of data and allows or denies them based on specified
criteria.
Stateful Inspection: Maintains the state of active connections and makes decisions based on
the context of the traffic.
Intrusion Detection/Prevention System (IDS/IPS): Monitors and analyzes network traffic for
suspicious activity, preventing or responding to potential attacks.
VPN Support: Enables secure communication over virtual private networks.

13. Explanation:
The Internet Filter-Proxy Server intercepts web
requests from users and filters content based on
specified rules, ensuring secure and controlled
internet access.
The Network Filter (Firewall) monitors all incoming
and outgoing network traffic, enforcing security rules
to protect the internal network from unauthorized
access and potential threats.
Features such as packet filtering, stateful inspection,
IDS/IPS, and VPN support contribute to a robust
network security posture.
This combined solution provides a layered approach
to security, addressing both internet content filtering
and network-level threats, contributing to a more
secure and resilient head office network.

14. Features of File permission types
in Linux systems
Read Permission (r):
Description: The read permission allows users to view the contents of a file or view the names of
files within a directory.
Critical Aspects:
Security: Read permission is essential for opening and reading files, but it doesn't allow
modification or execution. It is crucial for protecting sensitive information.
Directory Access: In the case of directories, read permission is necessary to list the files within the
directory.
Write Permission (w):
Description: The write permission allows users to modify the content of a file or create, delete, and
rename files within a directory.
Critical Aspects:
Data Integrity: Write permission is powerful and can lead to data modification or deletion. It's critical
to restrict this permission for important files to prevent accidental or intentional data loss.
Directory Modifications: In directories, write permission is necessary to create, delete, or rename
files.

15. Execute Permission (x):
Description: The execute permission allows users to execute a file if it is a program or a script. For
directories, it grants the ability to access the contents of the directory.
Critical Aspects:
Program Execution: Execute permission is vital for running executable files or scripts. For security, it's
important to limit execute permissions to authorized users and programs.
Directory Access: Execute permission on directories is necessary to change into the directory or
access its contents.
File Ownership:
Description: Every file and directory in Linux is associated with an owner and a group. File ownership
determines who has control over the file's permissions.
Critical Aspects:
Security Control: Owners have the authority to change permissions and modify the file. It's crucial to
ensure that only authorized individuals have ownership rights for sensitive files.

16. 1.Special Permissions:
1. Description: Special permissions include the setuid (SUID), setgid (SGID),
and sticky bit. These modify the behavior of the standard permissions.
2. Critical Aspects:
1.SUID/SGID: Allow a file to be executed with the permissions of the
owner/group, regardless of the user executing it. Commonly used for
system executables.
2.Sticky Bit: On directories, it prevents users from deleting or renaming files
owned by other users.
2.umask:
1. Description: The umask is a default permission setting applied when a new
file or directory is created. It works by subtracting the umask value from the
maximum permissions.
2. Critical Aspects:
1.Security by Default: Setting an appropriate umask helps in enforcing
security practices by defining the default permission settings for new files
and directories.

17. 20XX presentation title 17
Critical Considerations:
•Principle of Least Privilege: Only grant the minimum required permissions to
users and groups to perform their tasks, reducing the risk of unauthorized access
or modifications.
•Sensitive Files: Identify and protect sensitive files with strict permissions. Avoid
giving unnecessary write or execute permissions to critical files.
•Regular Audits: Regularly audit file permissions to ensure they align with
security policies and principles.
In summary, Linux file permissions are a fundamental aspect of system security,
controlling access to files and directories. A thoughtful approach to setting and
managing these permissions is essential for maintaining the integrity and
confidentiality of data on a Linux system.

21. Data redundancy technology is important for every single
organization, For above scenario evaluated data usage amount is
7 (Seven) Terabyte considering 5 (five) years future expansion in
File Server… Suggest how many disks you will use for above
scenario and what type of RAID system you will choose

22. To determine the number of disks and the appropriate RAID system for the
given scenario, we need to consider factors such as data redundancy, capacity,
performance, and future expansion. Here's a general recommendation based
on the provided information:
Factors to Consider:
1.Data Redundancy: Ensuring data redundancy is crucial for data protection
and recovery in case of disk failures.
2.Capacity: The total storage capacity required is 7 Terabytes, considering a 5-
year future expansion.
3.Performance: RAID systems can offer improved read/write performance
depending on the configuration.

23. Recommendation:
Given the importance of data redundancy and the need for future expansion, a
RAID 6 configuration is a suitable choice. RAID 6 provides fault tolerance even
in the event of the simultaneous failure of two disks.
Here's a suggested configuration:
1.RAID Type: RAID 6
1.Description: RAID 6 uses block-level striping with double distributed
parity. It requires a minimum of 4 disks and can withstand the failure of
up to 2 disks without data loss.
2.Advantages: Excellent data redundancy, suitable for environments
where data integrity is a priority.
2.Number of Disks:
1.Calculation: Given the total storage requirement of 7 Terabytes and
considering future expansion, it's advisable to use larger-capacity disks,
such as 4 Terabyte disks.

24. Total Storage Capacity:
•2 disks×4 TB per disk=8 TB total capacity2disks×4TB per disk=8TB total capa
city.
1.Disk Selection:
1.Choose enterprise-grade, reliable hard drives with sufficient capacity. Given
that data usage is projected to be 7 terabytes, considering future expansion,
you might opt for 2TB or 4TB drives depending on your budget and the
available options.
2.Number of Disks:
1.To achieve data redundancy and performance, a common approach is to use
RAID 6 or RAID 10.
2.RAID 6 provides redundancy with distributed parity across all drives,
allowing for the failure of up to two drives without data loss.
3.RAID 10 provides redundancy by mirroring and striping data across pairs of
drives. It can withstand the failure of one drive in each mirrored pair.

25. 1.Calculations:
1. If you choose RAID 6, you will need at least four drives to achieve 7 terabytes of usable space.
With 2TB drives, you would have a total raw capacity of 8TB (4 drives * 2TB), and 6TB usable
space.
2. If you choose RAID 10, you will need at least four drives as well. With 2TB drives, you would
have a total raw capacity of 4TB (4 drives * 2TB), and 4TB usable space.
2.Consideration for Future Expansion:
1. To accommodate future expansion, it's advisable to plan for additional capacity. You might
consider using larger drives or leaving empty drive bays for future additions.
2. If you anticipate significant growth, you might want to consider starting with larger drives or a
RAID controller that supports expansion with additional drives.
1.RAID Controller:
1. Ensure that you have a RAID controller that supports the chosen RAID level and provides
features like hot-swapping for easy maintenance.
2.Backup Strategy:
1. Regardless of the RAID configuration, always implement a robust backup strategy. RAID is not
a substitute for regular backups, as it doesn't protect against data corruption, accidental
deletions, or catastrophic events like fires or floods.

26. Evaluate the storage technology NAS (Network Attached
Storage) and SAN (Storage Area Network)

27. Network Attached Storage (NAS):
1.Definition:
1. NAS is a storage device that is connected to a network and provides file-based data storage services to other devices
on the network.
2.Architecture:
1. NAS devices are standalone units with their own operating system and file system. They typically use standard network
protocols like NFS (Network File System) or SMB (Server Message Block) for file access.
3.Use Case:
1. Ideal for environments where multiple users or devices need shared access to files, such as in small to medium-sized
businesses, homes, or offices.
4.Scalability:
1. NAS systems can be easily scaled by adding additional NAS devices to the network. Each NAS unit operates
independently and contributes to the overall storage pool.
5.Management:
1. NAS devices are generally easy to manage with user-friendly interfaces. Configuration and maintenance are typically
straightforward.
6.Performance:
1. Suited for file-level access. While modern NAS systems can provide good performance, they may not be as optimized
for block-level access as SANs.
7.Cost:
1. Generally more cost-effective than SAN solutions, making them suitable for smaller organizations with budget
constraints.
8.Data Protection:
1. Typically includes features like RAID for data protection. Data is stored in a file system, and access permissions are
managed at the file level.

28. Storage Area Network (SAN):
1.Definition:
1. SAN is a high-speed network specifically dedicated to connecting and providing block-level access to storage devices
like disk arrays or tape libraries.
2.Architecture:
1. SANs are typically made up of interconnected storage devices, servers, and switches. They use protocols like Fibre
Channel or iSCSI for block-level access.
3.Use Case:
1. Suited for enterprise-level environments with high-performance requirements, such as large corporations or data centers.
Common in scenarios where applications demand direct access to raw storage.
4.Scalability:
1. SANs are highly scalable and can support large amounts of storage and multiple connected devices. Scaling may involve
adding additional storage arrays or expanding the SAN fabric.
5.Management:
1. SANs can be more complex to manage, often requiring skilled administrators. Configuration, zoning, and LUN (Logical
Unit Number) management are critical tasks.
6.Performance:
1. Ideal for block-level access, providing high-speed, low-latency access to storage. Suited for applications with stringent
performance requirements.
7.Cost:
1. SANs are generally more expensive due to the high-performance hardware and networking components required. They
are more suitable for organizations with substantial IT budgets.
8.Data Protection:
1. Features robust data protection mechanisms such as RAID, snapshotting, and replication. Access control is often
managed at the LUN level.

29. Considerations:
•Access Type:
• NAS: File-level access.
• SAN: Block-level access.
•Scalability:
• NAS: Scales by adding more NAS devices.
• SAN: Scales by adding storage arrays or expanding the SAN fabric.
•Performance:
• NAS: Suited for general file-sharing scenarios.
• SAN: Designed for high-performance applications.
•Complexity:
• NAS: Easier to manage.
• SAN: More complex, requires skilled administrators.
•Use Cases:
• NAS: Small to medium-sized businesses, general file sharing.
• SAN: Large enterprises, high-performance applications, databases.

30. Discuss the network design with suggested services for above
scenario with a logical diagram, Name servers (Firewall, Central
Authentication, Telephony, File Server, CMS server) with NOS
types

31. +------------------+
| Internet |
+------------------+
|
+------------------+
| Firewall | (Linux-based)
+------------------+
|
+-------------------+ +------------------+ +------------
-------+
| Central | | Telephony | | CMS
Server |
| Authentication | | Server | |
|
| Server | | | | |
+-------------------+ +------------------+ +------------
-------+
|
+------------------+
| File Server | (Linux-based)
+------------------+

32. Overview of Servers:
1.Firewall:
1. Description: A Linux-based firewall to control and monitor incoming and outgoing network traffic.
2. Services: Packet filtering, stateful inspection, and intrusion detection/prevention.
3. NOS Type: Linux-based firewall software.
2.Central Authentication Server:
1. Description: A server responsible for central user authentication, ensuring secure access to network
resources.
2. Services: LDAP (Lightweight Directory Access Protocol) for user authentication.
3. NOS Type: Linux-based with LDAP services.
3.Telephony Server:
1. Description: Manages telephony services, possibly an IP-PBX (Internet Protocol - Private Branch
Exchange) system.
2. Services: VoIP (Voice over Internet Protocol) for internal communication.
3. NOS Type: May run on a specialized telephony operating system or a Linux-based system.
4.File Server:
1. Description: A Linux-based server responsible for storing and sharing files within the organization.
2. Services: NFS (Network File System) or SMB/CIFS for file sharing.
3. NOS Type: Linux-based file server.
5.CMS Server:
1. Description: Hosts the Content Management System (CMS) for managing and updating the company's
website content.
2. Services: Web server (e.g., Apache or Nginx) and CMS platform services.
3. NOS Type: May run on a Linux-based server.

33. Considerations:
Security: Implement strict access controls, VPNs, and regular security
updates.
Scalability: Plan for scalability to accommodate future growth in terms of
users and services.
Redundancy: Consider redundant configurations for critical servers to
ensure high availability.
Backups: Implement regular backup strategies for data protection.
Monitoring: Use monitoring tools to track network performance and
security events.
This logical network design aims to provide a secure, scalable, and
efficient infrastructure for ABC Web Solutions, integrating various servers
to support their diverse operational needs. The Linux-based servers offer
reliability, flexibility, and cost-effectiveness for the specified services.

34. Suggest suitable Server solutions for following
services;
i. Central Authentication for all client computers
ii. Telephony PABX solution
iii. File server
iv. Content Management Systems (CMS) for pay
roll

35. Central Authentication for All Client Computers:
•Solution: LDAP (Lightweight Directory Access Protocol) Server
•Description: An LDAP server can serve as a central authentication solution for
client computers. It allows storing and managing user credentials in a directory,
providing a single point for authentication across the network.
•Recommendation: OpenLDAP is a widely used open-source LDAP server that is
suitable for implementing central authentication.
ii. Telephony PABX Solution:
•Solution: Asterisk
•Description: Asterisk is an open-source software implementation of a Private
Branch Exchange (PBX). It supports VoIP and can provide telephony services,
including call routing, voicemail, and conferencing.
•Recommendation: Asterisk is a powerful and flexible option for implementing a
Telephony PABX solution. It can be customized to meet specific business
requirements.

36. iii. File Server:
•Solution: Samba or NFS (Network File System)
•Description:
• Samba: Samba is a software suite that provides file and print services for
Windows and Unix/Linux systems. It allows seamless file sharing between
different operating systems.
• NFS: NFS is a distributed file system protocol that allows a client to access files
over a network as if they were on its local disks.
•Recommendation: Choose Samba if the network has a mix of Windows and Linux
clients. Choose NFS for an environment predominantly using Unix/Linux systems.
iv. Content Management System (CMS) for Payroll:
•Solution: WordPress with Payroll Plugin
•Description: WordPress is a popular CMS that can be extended with plugins. There
are specific payroll plugins available for WordPress that allow businesses to manage
payroll information within the CMS platform.
•Recommendation: Utilizing WordPress with a reputable payroll plugin ensures a
user-friendly interface for managing payroll data and integrates seamlessly with the
CMS platform.

37. Types of Content Management Systems (CMS):
1.Open Source CMS:
1. Description: Open source CMS platforms are freely available, and their source code is accessible for
users to modify. They often have a large community of developers contributing to their improvement.
2. Examples: WordPress, Joomla, Drupal.
2.Proprietary CMS:
1. Description: Proprietary CMS solutions are commercially licensed, and their source code is not available
to the public. They are typically backed by a company or vendor, providing support and additional features.
2. Examples: Adobe Experience Manager, Sitecore, Kentico.
3.Headless CMS:
1. Description: Headless CMS separates the content creation and storage from the presentation layer,
allowing flexibility in delivering content to different platforms and devices.
2. Examples: Contentful, Strapi, Kentico Kontent.
4.Traditional CMS:
1. Description: Traditional CMS combines content creation and presentation within a single system. They
are known for ease of use and are suitable for websites with straightforward requirements.
2. Examples: WordPress, Joomla, Drupal.
5.Enterprise CMS:
1. Description: Enterprise-level CMS solutions are designed to handle large-scale websites and complex
digital experiences. They often offer advanced features, scalability, and robust security.
2. Examples: Adobe Experience Manager, Sitecore, Kentico.

38. Suitable HR System for Payroll:
For an HR system that includes payroll functionalities, considering the given scenario, the following HR/payroll
software is suggested:
Suggested HR System:
•System: ADP Workforce Now
•Description: ADP Workforce Now is a comprehensive human resources and payroll solution suitable for medium
to large-sized businesses. It offers features such as payroll processing, time and attendance tracking, benefits
administration, and HR management. It can integrate with various systems and provides compliance support.
•Key Features:
• Payroll processing and tax compliance.
• Time and attendance tracking.
• Benefits administration.
• HR management and employee self-service.
• Compliance support.
Considerations:
•Scalability: ADP Workforce Now is suitable for organizations with a growing workforce.
•Integration: Ensure that the HR system can integrate with other systems, such as the CMS and central
authentication server, for seamless data flow.
•Security: Choose an HR system that prioritizes data security, especially when dealing with sensitive payroll
information.

39. 1.WordPress:
1. Description: Extremely popular and user-friendly CMS. A vast array of plugins is available, making it
suitable for various purposes.
2. Suitability for PayPal Integration: WordPress has numerous plugins, such as WooCommerce, that allow
seamless integration with PayPal for e-commerce and online payments.
2.Joomla:
1. Description: A versatile CMS with a strong community and extension ecosystem. It's known for its
flexibility and scalability.
2. Suitability for PayPal Integration: Joomla supports various e-commerce extensions, including those with
PayPal integration capabilities.
3.Drupal:
1. Description: A highly customizable and flexible CMS with a robust framework. It's suitable for complex
websites and applications.
2. Suitability for PayPal Integration: Drupal Commerce is an e-commerce module for Drupal, providing
features for online transactions, including PayPal integration.
4.Magento:
1. Description: Primarily an e-commerce platform, Magento is powerful and scalable, suitable for medium to
large-sized online stores.
2. Suitability for PayPal Integration: Magento has built-in support for PayPal, allowing for seamless
integration and online payment processing.
5.PrestaShop:
1. Description: A user-friendly e-commerce solution that is lightweight and easy to set up.
2. Suitability for PayPal Integration: PrestaShop supports multiple payment gateways, including PayPal, for
online transactions.

40. 1.OpenCart:
1. Description: A simple and straightforward e-commerce solution, suitable for small to
medium-sized online stores.
2. Suitability for PayPal Integration: OpenCart has built-in support for PayPal, making it
easy to integrate and use for online payments.
2.Grav:
1. Description: A modern flat-file CMS that is lightweight and fast, suitable for smaller
websites and projects.
2. Suitability for PayPal Integration: While Grav itself doesn't have built-in e-commerce
features, plugins/extensions can be added for PayPal integration if needed.
Note: When implementing PayPal or any payment gateway integration, always ensure that the
CMS and associated plugins/extensions are kept up-to-date for security reasons.
The suitability of a CMS for PayPal integration also depends on the specific requirements of your
payroll functionalities. If the focus is on payroll processing and not e-commerce, a CMS like
Drupal, with customizable forms and workflows, may be more appropriate. Always check the
documentation and community support for each CMS to ensure it aligns with your project's goals.