Lesson Notes By Weeks and Term v5 - Grade 12

Lesson Video

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Performance objectives

• Analyze system performance issues and recommend solutions.
• Implement basic security measures to protect systems.
• Design a backup and recovery strategy.
• Describe different network topologies.
• Explain the importance of regular software updates.

Lesson summary

This week, we delve into the critical aspects of system and network performance, security, and backups. In our increasingly digital world, these elements are essential not just for large corporations but also for small businesses, schools, and even individual users in South Africa. Imagine a small spaza shop losing all its sales data due to a virus or a school being unable to access online learning resources because of slow internet speeds. These scenarios highlight the real-world impact of poor system and network management. We’ll explore how to optimize system performance, protect against cyber threats, and safeguard valuable data through effective backup strategies.

Lesson notes

2.1 System Performance Optimization System performance refers to the efficiency and responsiveness of a computer system. Slow performance can be caused by a variety of factors, including: Hardware limitations: An outdated or underpowered CPU, insufficient RAM, or a slow hard drive can all bottleneck performance. Upgrading these components can significantly improve system speed. For example, replacing a traditional HDD with an SSD dramatically improves boot times and application loading speeds. Think of it like upgrading from a donkey cart to a taxi – the destination remains the same, but the speed increases significantly.

Software bloat: Too many programs running simultaneously or unnecessary software installed can consume system resources and slow down performance. Regularly uninstalling unused programs and disabling unnecessary startup applications helps.

Fragmented hard drive: Over time, files become fragmented on the hard drive, making it take longer for the system to access them. Disk defragmentation reorganizes these files for faster access.

However, this is not applicable to SSDs.

Malware: Viruses, spyware, and other malware can consume system resources and significantly degrade performance. Regularly scanning with an antivirus program is crucial.

Operating system issues: A corrupted operating system or outdated drivers can also cause performance problems. Reinstalling the OS or updating drivers can resolve these issues.

Example: Imagine a school computer lab where the computers are running slowly. After investigation, it's found that the computers have old hard drives, are infected with malware, and have many unnecessary programs installed. To improve performance, the school could: Upgrade the hard drives to SSDs. Install and run a reputable antivirus program. Uninstall unused software. Defragment the hard drives (if they're HDDs). Increase RAM if needed. 2.2 Network Topologies and Performance A network topology describes the physical or logical arrangement of devices in a network.

Common topologies include: Bus Topology: All devices are connected to a single cable (the bus). Simple to set up, but a break in the cable can disrupt the entire network. Performance degrades as more devices are added due to collisions.

Star Topology: All devices are connected to a central hub or switch. Offers better performance and reliability than a bus topology. A failure of one device doesn't affect the rest of the network. The central hub/switch is a single point of failure.

Ring Topology: Devices are connected in a closed loop. Data travels in one direction. A break in the ring can disrupt the entire network.

Mesh Topology: Devices are interconnected with multiple paths. Offers high redundancy and reliability but is complex and expensive to implement.

Tree Topology: A combination of bus and star topologies. Commonly used in large organizations. The choice of network topology significantly impacts performance and security. A star topology with a switch is generally preferred for its performance and manageability. Switches intelligently forward data only to the intended recipient, reducing collisions and improving efficiency.

Example: Consider a small office setting up a network. They have a choice between a bus and a star topology. The star topology with a switch is the better choice because it offers better performance, scalability, and fault tolerance. If one computer fails in a star topology, the rest of the network remains operational. 2.3 Security Measures Security is paramount in protecting systems and networks from unauthorized access, data breaches, and malware.

Key security measures include: Firewalls: Act as a barrier between the network and the outside world, blocking unauthorized traffic. Both hardware and software firewalls are available.

Antivirus software: Detects and removes malware from systems. Regular scanning and updates are crucial.

Strong passwords: Using strong, unique passwords for all accounts is essential. A password manager can help.

Two-factor authentication (2FA): Adds an extra layer of security by requiring a second form of verification, such as a code sent to a mobile phone.

Regular software updates and patching: Software updates often include security patches that fix vulnerabilities. Keeping software up-to-date is crucial. Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS): These systems monitor network traffic for suspicious activity and can automatically block or mitigate threats.

User access control: Limiting user access to only the resources they need helps to prevent unauthorized access and data breaches.

Example: A clinic needs to protect patient data. They should implement the following security measures: Install a firewall to protect their network from unauthorized access. Use strong passwords and enable two-factor authentication for all accounts. Regularly update their operating systems and software. Install and run antivirus software on all computers.