Advanced Computer Maintenance SS3 Computer Hardware & GSM Repair Lesson Note

Subject: Computer Hardware and GSM Repair 

Class: SS3 

Topic: Server Maintenance and Virtualization Basics 

The “Super-Computers” of the Network

We are used to laptops and desktop computers, but have you ever wondered where a website like Jumia or a bank’s mobile app lives? They don’t live on a regular PC. They live on a Server.

A server is a powerful computer that stays on 24 hours a day, 7 days a week. Its only job is to “serve” data to other computers. If a regular computer is like a private car, a server is like a massive city bus—it carries many people at once and must never break down in the middle of the road.

Server Maintenance: Keeping the Engine Running

Because servers never sleep, they get tired and dirty faster than regular PCs. Maintenance is the “health check” we perform to prevent a total shutdown.

Physical (Hardware) Maintenance:

• Dusting: Servers have many fans to stay cool. Dust blocks these fans, causing the server to overheat and “fry” its brain (the CPU). We use compressed air to blow out dust every few months.
• Redundancy Checks: Servers usually have two power supplies and many hard drives. If one fails, the second one takes over. We must check periodically to ensure the “spare” parts are actually working.
• Cable Management: A messy server room is a dangerous one. Cables must be labeled and tied neatly so you don’t pull the wrong one by mistake.

Software Maintenance:

• Security Patches: Hackers are always looking for “holes” in a server’s software. We must install updates (patches) to close these holes.
• Log Reviews: The server keeps a “diary” of everything that happens. By reading these logs, a technician can see if a hard drive is starting to fail before it actually dies.
• Backups: This is the #1 rule. Always have a copy of the data stored somewhere else (like in the Cloud or on a separate disk).

Virtualization: Making One Computer Act Like Many

In the old days, if a company wanted to run a website, an email system, and a database, they had to buy three separate physical servers. This was expensive and wasted a lot of electricity.

Virtualization is a technology that allows us to take one very powerful physical server and “split” it into several smaller, “virtual” computers.

How it works:

We use a special software called a Hypervisor (like VMware or VirtualBox). The Hypervisor sits on the physical hardware and creates “Virtual Machines” (VMs). Each VM thinks it is a real computer with its own Windows or Linux system, but they are all actually sharing the same physical box.

Why is this great?

• Saves Money: You buy one big server instead of five small ones.
• Easy Recovery: If a virtual machine gets a virus, you can “delete” it and restore a fresh copy in minutes without touching the physical hardware.
• Energy Efficient: Less heat and less electricity are used.

The Server Room Environment

A server’s biggest enemies are Heat and Moisture.

1. Cooling: Server rooms must have strong Air Conditioning. The temperature should be like a cold fridge (around 18°C – 22°C).
2. Uninterruptible Power Supply (UPS): You cannot plug a server directly into a wall socket. You must use a large UPS. If the “light” goes out, the UPS provides battery power for enough time to turn the server off safely or switch to a generator.
3. Physical Security: Only authorized technicians should have the key or code to the server room. One person accidentally pulling a cable can shut down an entire company.

Troubleshooting Server Issues

When a server “goes down,” everyone in the office stops working. You must act fast:

• Step 1: Check the Lights. Servers have “status LEDs.” If you see a blinking orange or red light, that part (usually a hard drive or power supply) is failing.
• Step 2: Remote Access. Use a laptop to try and “Ping” the server. If it responds, the hardware is okay, but the software might be “stuck.”
• Step 3: The Restart. In the server world, we call this a “Reboot.” It is the last resort but often clears up memory errors that make the system slow.

Summary

Server maintenance and virtualization are the “High-Level” skills of a computer technician. While others are fixing broken screens, you are managing the systems that run the world’s internet. It requires a lot of responsibility, but it is one of the most respected jobs in ICT.

Review & Practical Exercises

1. Explain why “dust” is more dangerous for a server than it is for a regular desktop computer.
2. What is a Hypervisor, and what is its role in virtualization?
3. Why do we need a UPS in a server room?
4. Define the term “Redundancy” in your own words. Why is it important for a bank’s server?