A+ Fundamentals: Mainframes To Cloud | IT Skills Development Chapter 8

Detailed technology education and IT skills development guide covering mainframes to cloud computing for CompTIA prep.

One idea rewired computing: what if one machine could convincingly pretend to be many? We start with mainframes and time sharing, then move through hypervisors, virtual machines, and the moment virtualization became the backbone of the cloud. From there, the story accelerates into public, private, hybrid, and community cloud models, and the service stack that defines modern IT—Infrastructure as a Service, Platform as a Service, and Software as a Service—so you know exactly who manages what and why it matters.

We break down how to build reliable VMs, choose the right network mode, and use snapshots, templates, and live migration to save time and prevent outages. Then we climb the stack to cloud storage options like object, block, and file; explore VDI with thin and zero clients for secure, centralized desktops; and map the virtual network layer with routers, firewalls, load balancers, and VPN gateways. Security threads through everything: shared responsibility, IAM, MFA, encryption, and redundancy. You’ll learn practical troubleshooting for slow VMs, networking quirks, sync failures, and common cloud gotchas like quota limits and VPN interference.

Containers and Kubernetes bring speed and resilience, turning monoliths into microservices that scale on demand. We close on the frontier—edge and fog computing reduce latency at the source, while serverless lets code run only when needed. By the end, you’ll see how virtualization delivered flexibility, the cloud delivered scale, containers delivered agility, and serverless delivered automation. Subscribe, share with a teammate, and leave a quick review to help more tech learners tap into the roots and future of cloud computing.

Chapters

• 0:27 Welcome And Episode Setup
• 1:16 Origins Of Virtualization
• 2:30 Hypervisors Explained
• 3:59 Building And Managing Virtual Machines
• 5:11 Network Virtualization Modes
• 6:01 Real-World Virtualization Scenarios
• 6:59 Virtualization As Cloud’s Backbone
• 8:03 What The Cloud Really Is
• 8:46 Cloud Deployment Models
• 10:23 Cloud Service Models
• 11:45 Cloud Storage Options
• 13:08 VDI And Thin Clients
• 14:15 Cloud Networking And Security
• 15:28 Edge, Fog, And Serverless
• 16:31 Containers And Orchestration
• 18:48 Cloud Backup Strategies
• 20:24 Cloud Printing And Services
• 21:15 Troubleshooting Virtual Machines
• 22:20 Troubleshooting Cloud Issues
• 23:45 Future Trends And Mindset
• 25:26 A+ Practice Questions
• 30:56 Closing And Contact Info

Transcript

SPEAKER_00: 0:27

And welcome to Technology Tap. I'm Professor J. Rod in this episode Cloud Concepts. Let's tap in the event. Cloud concepts and virtualization. This is a story not just machines but of imagination. A story of how we learned to take one physical system and make it many. Today the cloud is everywhere, powering your phone, your bank, your classroom, your hospital, your entertainment. But it didn't begin that way. It started with one idea. How can a computer pretend to be another computer? Let's go back to where it all began. The origins of virtualization. Mainframes filled entire rooms humming like metallic giants. They were expensive, too expensive for every department to get their own machine. So IBM asked the question that birthed virtualization. What if one computer can pretend to be many? Using early forms of time sharing, they allowed different users to run processes individually individually, independently, each isolated, each protected. It was the seeds of modern virtualization. Every breakthrough starts with a limitation. Fast forward into the 1990s, as personal computers grew, powerful companies like VMware revived the concepts. Their creation, the hypervisor. And with it, virtualization leaped from mainframes into desktops of IT professionals everywhere. Hypervisors Behind the Magic. To understand virtualization, you must understand hypervisors. They are software or firmware that allows multiple virtual machines to run up on a single physical computer. Type 1 hypervisor, also called the bare metal hypervisors, these run directly on the hardware. Examples VMware ESXi, Microsoft Hyper B server, Zen, KVM. They use in enterprise servers, data centers, and cloud providers, places where performance and stability matter. Then we have your type 2 hypervisors, also called host hypervisors. These run as applications inside of normal operating systems. Example, VMware Workstation, VMware Fusion, Oracle VirtualBox, Parallels Desktop. These are ideas for labs, these are ideal for labs education and desktop testing, where convenience matters more than absolute speed. Type 1 is a pilot flying the plane. Type 2 is a passenger flying a simulator. Virtual machines, the digital blueprint. A virtual machine is a complete system, CPU, memory, storage, network, all simulated in software. As a technician, you define virtual CPU count, virtual RAM amount, virtual hard disk space, network type where it's NAT, bridge, or host only, shared folders, graphic acceleration, UEIF and BIOS firmware type. Camtea calls these virtualization requirements and you configure them consistently in the field. Snapshots these freeze a VM in time, allowing quick rollback, invaluable for labs, malware analysis, OS testing. VM templates, clones, used by IT teams to deploy many identical systems. Every cloud service does this behind the scenes. VM migration moving a VM from one physical host to another, sometimes while running using technologies like VMotion or live migration. A VM machine is more than a machine. It's a story saved in silicon. Network virtualization. Modern virtualization doesn't stop with CPU and RAM. The network itself can be virtualized. You can have virtual switches, software-based switches inside hypervisors. They connect VMs to each other and to the outside world. Virtual Nix, every VM gets its own network interface card, fully independent, fully configurable. NAT Mode, VM shares the host IPs, good for isolation. Bridge mode, VMs act like a real machine on the land, great for labs. Host only mode, isolated network between VM and host, perfect for malware labs. And virtualization networks aren't built with cables, they're built with choices. Virtualization in the real world. Scenario 1, testing malware safely. You spin up a VM, isolate it, infect it intentionally, and learn from it. Your physical PC is safe. Scenario 2, supporting legacy applications. Run it in a VM for security safety, right? Scenario 3, classroom labs. Students get a virtual machine with standardized imaging. No physical hardware is needed. Great when you're running access, but you don't have a Windows PC and you only have a Mac. Scenario 4, rapid OS deployment. Need 10 Windows 11 installation, clone a template VM. Virtualization stamp saves time, cost, and effort. The bridge to the cloud. Virtualization is not separate from cloud computing. It's the backbone. Every cloud server relies on hypervisor clustering, resource pooling, orchestration, VM scaling. Before the cloud could become the cloud, virtualization had to mature. The cloud is just virtualization at a planetary scale. Into the cloud. Now we step into the clouds, the simmering layer of computing that transformed the world. What began as simple virtualizations has become a global platform billings rely on every moment. From startups to megacorporations, universities to hospitals, schools to smart homes. The cloud is the invisible engine powering modern life. Virtualization is the foundation. The cloud is the skyscraper. Let's ascend. What is the cloud? To understand the cloud, remove the mystery. It's just someone else's data center built with virtualization on a massive scale. At its core, cloud computing offers virtualized resources shared across many users, delivered over the internet, on-demand, scalable, and elastic. Think of it like electricity. You don't generate it, you simply use it. You pay for what you consume. The cloud works the same way. The cloud didn't change computing, it changed access. Cloud deployment model. Comti A Plus emphasized four major cloud deployment models. Let's bring each to life. One, public cloud, hosted by third-party providers like Amazon Web Service, Microsoft Azure, Google Cloud Platform. Anyone can sign up. You share the underlying hardware with other customers, securely, of course. Best for smart businesses, startups, anyone wanting flexible pricing, anyone needed global scaling. Two, private cloud. A private cloud is owned or dedicated to one organization. It can be on premise on your own data center, hosted by a third party, fully managed by internal IT, used by governments, hospitals, financial institutions, enterprise restrict compliance requirements. Third one is the hybrid cloud. A hybrid cloud mixes public and private cloud. Sensitive data stays local. Services scale outward into the public cloud when needed. Great for bursting workloads, disaster recovery, organizations transitioning gradually to the cloud. Hybrid isn't a compromise, it's a bridge. Then you have community cloud. Shared by organizations with the same mission or regulatory needs. Like universities, research groups, government agencies, healthcare collaboration. A rare model, but it's still on the exam. Cloud service models. Now we reach the three pillars of cloud computing. COMPTIA demands mastery of all three. Infrastructure as a service. You rent the building blocks, virtual VMs, storage, networking, firewalls, load balancing. Examples AWS EC2, Azure Virtual Machine, Google Compute Engine. You manage the OS, you manage the apps, they manage the hardware. Platform as a service. Developers rent an environment to build apps. You get runtime environments, databases, APIs, dev framework, automatic scaling. Example, Google App Engine, AWS Elastic Beanstalk, Azore App Service. Don't worry about servers. You focus on the code. Last, software as a service. Applications deliver fully ready to use. Google Workspace, Microsoft 365, Salesforce, Dropbox, Zoom, Slack. You just log in. Everything else is handles for you. SaaS, software as a service, is the reason modern workforce operates anywhere. Cloud storage models. Cloud storage is a core A concept. Major types, object storage, used by services like Amazon S3, massive scalability. Cheap, great for backup. Block storage, high performance, used for virtual hard drives. File storage, network shares in the cloud, like Azure Files or AWF EFS. Cloud storage revolutionized backups. Disaster recovery. Collaboration. Phone video archiving. Software deployment. Your phone right now silently silently syncs to the cloud storage. Your laptop backs up probably goes to a cloud target. Your social media cloud. Your email cloud. Examples, Citrix Virtual Apps and Desktops, VMware Horizon, Microsoft Azure Virtual Desktop. Imagine 2,000 employees locking into an identical desktop, all patched, all identical, all controlled centrally. That's VDI. Think clients and Zero Clients. Think clients are lightweight devices with minimal storage, minimal CPU, just enough power to connect to a BDI session. They depend entirely on the server. Zero clients take this even further. No OS, no storage, just firmware. Used where security is critical. Maintenance must be minimal. IT infrastructure wants full control. But a thin client could be something like a Google Chromebook, right? Because everything is handled in the cloud when you do Google Google Classroom, you know, the Google laptops that the people use in schools. So that could be another example. Cloud networking. The cloud uses virtual networking, virtual routers, virtual firewalls, load balancers, security groups, VPN gateways. When you connect to a cloud service, you're entering a virtualized network space. Every connection is routed, filtered, secure, and logged. All inside software. Camtia A Plus includes VPN connections, remote access, on-demand scalability, cloud-hosted services like VoIP, cloud-hosted applications. Cloud security concepts. Security is when cloud computing becomes critical. Key topics include share responsibility model. Cloud provider handles the infrastructure, you handle the data, identities, permissions, and configurations. Multifactor authentication, essential for cloud access. Identity and access management. Who can access which resources? Data redundancy, multiple availability zones, prevent data loss. Encryption in transit and at rest. The cloud is secure, but only if you are. Edge, fog, and serverless computing. Edge computing. Processing done close to where data is created. Used in smart cameras, IoT devices, industrial sensors, smart cars, environmental monitoring. Fog computing. Distributed computing between cloud and edge. Like mist between the ground and the sky. Serverless computing. You run code without managing servers. AWS Lambanda, Azure Functions, Google Cloud Functions. You pay per execution, not per server. The cloud is no longer a place, it's a continuum. We've traveled from mainframes to hypervisors, from SAAS to serverless, from inclines to global cloud infrastructure. Now we explore the cutting edge layer that defines modern IT. Containers, troubleshooting, cloud connectivity, backup strategies, and real-world A plus operation. This is where theory becomes practice, where technicians turn knowledge into actions. Virtualization built the cloud. Containers and orchestration will build the future. Let's begin. Containers virtual versus virtual machines. Virtual machines simulate an entire computer. Hardware, OS, drivers, the whole Slack. Containers, they just simulate just the application environment sharing the host kernel. Think of it like this. VM is a whole apartment, and the container is a single room inside a share house. The advantages? Lightning fast startup, extremely lightweight, high density deployment, ideal for microservices, portable across environments. Popular tools, Docker, the most famous container engine. Contain nerd and podman. Containers revolutionized development and cloud operations. Virtual machines created flexibility. Containers created agility. Orchestration, running thousands of containers. If containers are rooms, orchestration tools are the building managers. They deploy containers, scale them automatically, monitor their health, replace ones that fail, balance load, coordinate network. The key of orchestration, Kubernetes, developed by Google, now open source and used globally. Enterprise deployed hundreds, thousands, and even millions of containers daily. Technicians must understand that when they troubleshoot a modern web app, they may be interacting with 20 microservices running in 20 containers, distributed across three regions, managed by Kubernetes, backed by cloud storage, running load balancers. This is the invisible machinery behind apps like Netflix, Amazon, TikTok, even your banking apps. Cloud backup strategies. Cloud backup models are central to Comtia A Plus. Here's what every technician must know. File level backups. Only specific folder sync. OneDrive, Google Drive, Dropbox, iCloud. Perfect for end user devices. Two, image level backups. Full system snapshots stored in the cloud. Use in enterprise disaster recovery. Three, incremental backups. Only changes since the last backups are saved. Efficient, fast, and used across modern cloud platforms. Four differential backups. Store changes to the last full backup. Larger than incremental but quicker restore points. Five, offsite replication. Data copy to another region or availability zone. This protects against ransomware, natural disasters, data center outage. Reflection. Backups are an optional in the cloud. They're survival. And if you're in charge of the backup and you're not doing the backup like you should, you are one day going to find out the hard way, if you're not doing your backups right, when it will fail. Because eventually it will fail. And if you don't have a good backup, you might not have a job. Cloud printing and cloud-based services. A plus includes a surprisingly practical cloud feature, cloud printing. Example, Google Cloud Print, retired for important historically. Manufacture Cloud Solutions, HP Smart, S Bin Connect, Brother Cloud Benefits, Remote Printing, Mobile Device Compatibility, Centralized Cues, Reduce Local Driver Management. You'll see the cloud printing heavily in school districts, remote offices, businesses with traveling staff, shared workspaces. Other cloud-based services include cloud-based VoIP, cloud authentication, cloud patching patching systems, and cloud antivirus and EDR platforms. All part of the modern technician workflow. Troubleshooting virtual machines. Now we enter the real technician's arena. Troubleshooting virtualization. Here are the most common issues you face and how you will fix them. VM runs slowly, causes not enough VRAM, too many V CPUs assigned, disc IO saturation, host CPU at 100%, background snapshot consuming space. Solution reduce VM count, increase host memory, allocate fewer V CPUs, cleanup snapshots, and move VM storage to SSD or NVMe. Second one, VMs won't start. Possible issues, insufficient host resources, corrupt VM image, missing virtualization support, Intel VT or AMD-V disabled. Solution Enable virtualization in BIOS or UEFI, free up host memory, and restore VM from snapshot. Number three VM has no connections. Check NAT vs bridge mismatch wrong virtual switch DACP disabled on host, firewall blocking VM. Solutions swap to bridge mode for land visibility, reassign virtual nick, restart virtual switch. Four VM freezes or crashes. Common causes. Overcommitted resources, unsupported operating system, or misconfigured hypervisor tool. Solution install integrated tools, balance workloads, increase host stability. Every VM is only as healthy as this host. Cloud troubleshooting. End users don't see virtualization, orchestration, or distributed systems. They see why can't I log in? Why is my drive not syncing? Why can't I print? Why does my cloud software look different today? Here's how A plus techs approach cloud troubleshooting. One, identify the problem. Most cloud failures stem from expired passwords, incorrect multi-factor authentication, disabled accounts, IMIAM misconfigurations. Log in from new device security blocks. Always check identity first. Second, sync conflicts. Cloud storage often fails due to running out of cloud space, file name restriction, offline mode versus online mode, and account mismatch. Number three, SaaS issue. Remember, you don't fix the service, you fix the client. Check, browser cache, app updates, permissions, network connectivity, VPN interference. Four cloud connectivity. A plus technicians always verify DNS, ping, trace route, VPN tunnels, proxy settings, local firewalls. When the cloud breaks, the issue usually begins on the ground. The future of virtualization, Edge, Fog and Beyond. Edge devices now process data when it's created. Automobiles, IoT sensors, smart refrigerators, factory reboots, security cameras. Fog computing acts as a local mini cloud between edge devices and the main cloud. And serverless computing is rapidly taking over. No servers to maintain, pay per request, scales automatically, ideal for microservices and automation. The cloud is no longer a destination, it's the default. So let's take a look at our four Camtia A plus questions. You know how we do it here. We I ask the questions, I say four times, and then I give you the answers. Alright, ready for the first question? Alright, let's see if you're ready. Let's try to get four out of four. And if you get four out of four, that means you almost ready for the COMT exam. Alright, question one. A technician creates a VM that shares the host IP address but cannot be reached from other devices on the LAN. Which network mode is most likely being used? A bridge B NAT C host only D VLAN trunk. I'll read it again. A technician creates a VM that shares the host IP address but cannot be searched from other devices on the LAN. Which network mode is most likely being used? A bridge B Nat C host only or D VLAN trunk. I'll give you five seconds. Think about it. 5, 4, 3, 2, 1. And the correct answer is B NAT. NAT mode lets the VM access the internet using the host IP, but other devices on the LAN cannot reach the VM. It is isolated behind the host NAT translation. Bridge would allow full LAN visibility. Host only isolates the VME even further. It can only talk to the host. And VLAN trunk has nothing to do with basic VM networking models. Alright. Question two. Which cloud model allows developers to deploy applications without managing any underlying servers? A IAAS B PAAS C SAAS or D serverless. Which cloud model allows developers to deploy applications without managing any underlying servers? A IAAS B PAAS C SAAS or D serverless. I'll give you five seconds to think about it. Five, four, three, two, one. And the answer is D, serverless. Serverless computing allows developers to run code without provisioning or managing servers. PaaS provides a development environment but still requires platform configuration. IAAS gives virtual machines full server management. And SaaS provides ready-to-use software, not a development platform. Alright, we're halfway there. Question three. An organization wants each employee to log into a standardized desktop environment that is centrally managed and maintained. What solution best fits this requirement? A VDI, B, thin provisioning, C container orchestration or D hybrid. An organization wants each employee to log into a standardized desktop environment that is centrally managed and maintained. What solution best fits this requirement? A VDI B thin provisioning C container orchestration or D hybrid cloud. I'll give you five seconds to think about it. Five, four, three, two, one. And the correct answer is A, VDI. VDI virtual desktop infrastructure delivers centralized, managed, uniform desktops to many users. Think provisioning is a storage technique, not a desktop solution. Container orchestration is for server applications, not user desktops. And hybrid cloud is a deployment model, not a desktop technology. Alright, hopefully you got three out of three. Let's do the last one and go four for four. A user reports that their cloud storage app stops syncing files. They are signed in and online, but syncing fails repeatedly. Which is the most likely cause? A corrupt CPU firmware, B insufficient cloud storage space, C incorrect hypervision hypervisor configuration, or D disabled BIOS virtual setting. I'll read it again. A user reports that the cloud storage app Stop syncing files. They're signed in and online, but syncing fails repeatedly. What is the most likely cause? A corrupt CPU firmware. B insufficient cloud storage space. C incorrect hypervisor configuration or D disabled BIOS virtualization setting. I'll give you five seconds to think about it. Five, four, three, two, one. The answer is B insufficient cloud storage. Running out of cloud storage quota is one of the most common syncing failures. CPU firmware corruption is irrevalent. Hypervisor configuration has nothing to do with cloud storage apps, and BIOS virtualization does not affect cloud syncing. Alright, raise your hand if you got four out of four. Hopefully you did. Hopefully, you're raising your hand up high. Congratulations if you did. Alright, let's wrap this up. Virtualization gave us flexibility, the cloud gave us scale, containers gave us speed, serverless gave us automation. We began with one physical machine pretending to be many. We ended with millions of machines working together as one. For today's technician, virtualization in cloud isn't just an exam objective, it's a map of how modern IT truly works. I'm Professor J. Rod and keep tapping into technology. Until next time. You can follow me at TikTok at Professor J Rod at J R O D, or you can email me at Professor J Rod, J R O D at Gmail dot com.