Modern digital technologies require flexibility that a physical computer cannot always provide. When developers are testing new programs, cybersecurity specialists are analyzing viruses, or ordinary users want to run an application designed for another operating system, it comes to the rescue virtualization. This is a technology that allows you to run one operating system inside another, creating a completely isolated software environment.
Imagine being able to install Windows inside macOS or run Linux on your regular Windows without having to reinstall the system or risk the stability of your host computer. That's exactly how it works virtual machine (VM). It emulates real hardware by providing the guest operating system with a virtual processor, memory, and hard drive that are actually part of your host's resources.
The use of such environments has become an industry standard because it provides security and convenience. If there is a failure or virus attack in the virtual environment, your main system will remain intact. You simply delete the damaged file or restore the previous one backup copy (snapshot) and continue working.
Operating principles and key terms
To effectively manage virtual environments, you need to understand basic terminology. The computer on which the emulation program runs is called host. The operating system that is installed inside the program is called guest. Between them there is a layer of abstraction - hypervisor, which distributes hardware resources between real and virtual tasks.
There are two main types of hypervisors. The first type (Type 1) is installed directly on the hardware and is used in server data centers. The second type (Type 2) is what the average user encounters. This is an application that you install on your laptop or PC, e.g. VirtualBox or VMware Workstation. It runs on top of your main OS.
⚠️ Attention: The virtual machine consumes the resources of your physical computer. If you run a heavy game or video rendering inside a VM, the main system may start to slow down due to lack of RAM or CPU power.
The most important aspect is file system isolation. The guest OS stores its data in a special container file on the host disk. To the outside world, this file looks like a single block of data, but inside it there may be a complex partition structure. This makes it easy to migrate entire computers simply by copying a single file.
Allocate no more than 50% of your computer's available RAM to the virtual machine to ensure the main system remains responsive.
Choosing the right software
The market offers many solutions for creating virtual environments, and the choice depends on your goals and budget. For home use and education, free and open source products are most often chosen. They have sufficient functionality for most tasks and support a wide range of guest operating systems.
Enterprise professionals often require paid solutions with advanced support and network management capabilities. Such products provide better graphics performance and deeper integration with host hardware, which is critical for developing complex applications or 3D modeling.
- 🟢 Oracle VM VirtualBox is the most popular free option for beginners, supporting Windows, Linux, macOS and Solaris.
- 🔵 VMware Workstation Player is a free version for personal use, known for its stability and excellent graphics performance.
- 🔴 Parallels Desktop - the best solution for Mac computer owners that allows you to run Windows applications without rebooting.
- 🟠 Hyper-V is a built-in tool in professional versions of Windows that does not require the installation of third-party software.
When choosing, you should pay attention to hardware virtualization support. Modern Intel and AMD processors have special instructions (VT-x and AMD-V), which significantly speed up the operation of virtual machines. Without their inclusion in the BIOS/UEFI, launching modern VMs may be impossible or extremely slow.
What is Nested Virtualization?
Nested virtualization is the ability to run a virtual machine inside another virtual machine. This is required for testing clusters or complex network configurations, but greatly reduces performance.
Step-by-step installation and initial setup
The process of creating a new machine begins with installing the selected hypervisor on the host. After starting the program, you need to create a new profile, specifying the type and version of the guest operating system. This is an important step, as it determines the optimal hardware emulation settings.
Next comes the resource allocation stage. You need to determine how many processor cores and how many gigabytes of RAM will be allocated to the guest. You also need to create a virtual hard disk. Typically, a dynamically expanding file format is used that grows as it fills with data, without immediately taking up all the space on the physical disk.
☑️ Setting up a new virtual machine
After creating the profile, you need to connect the ISO image of the installation disk to the virtual drive and start the machine. The process of installing the OS inside a VM is almost identical to installing it on a real computer: you select the language, disk layout and create an account. The only difference is the speed of the process, which depends on the speed of your physical drive.
| Parameter | Minimum value | Recommended value | Impact on the system |
|---|---|---|---|
| RAM | 2 GB | 4-8 GB | Application speed inside a VM |
| CPU cores | 1 core | 2-4 cores | Guest OS multitasking |
| Video memory | 16 MB | 128 MB and above | Smooth interface and video |
| Disk (SSD) | 20 GB | 60+ GB | Speed of downloading and installing programs |
Setting up integration and sharing
After successfully installing the operating system, the user is faced with the task of improving ease of use. By default, the virtual machine is isolated and sharing files with the host is difficult. To resolve this issue, you must install an add-on package, often called Guest Additions or VMware Tools.
These drivers allow you to implement folder forwarding, a shared clipboard, and drag-and-drop files between windows. Without them, the guest's screen resolution may not adapt to the size of the program window, and the mouse cursor will get stuck inside the virtual environment, requiring special key combinations to exit.
⚠️ Attention: When setting up shared folders, make sure that the latest anti-virus protection is installed inside the guest OS. Files infected with a virus on the host can be instantly copied to a shared folder and activated by the guest, or vice versa.
Network setup is another critical point. By default, NAT mode is used, when the virtual machine accesses the Internet through the host's IP address, remaining invisible to the external network. If you need other computers on the local network to see your VM as a separate device, you should switch the network adapter mode to Bridge (Bridge).
Installing Guest Additions is a mandatory step for comfortable work, ensuring the correct screen resolution and integration with peripherals.
State management and backup
One of the main advantages of virtualization is the ability to save the state of the system at any time. This function is called snapshot (snapshot). By taking a photo, you record the current state of memory, disk and settings. If after installing new software the system crashes, you can roll back to the previous restore point in seconds.
Snapshots are not a full backup in the classical sense. They only store changes that have occurred since the previous snapshot was taken. Therefore, the snapshot chain depends on the underlying state of the machine. Removing the base disk will render all subsequent snapshots useless.
You need to use this feature wisely. Storing multiple Snapshots can lead to severe file fragmentation on the physical disk and poor performance. It is recommended to take pictures before risky operations and delete them after you are sure that the system is stable.
- 📸 Creation — fixes the current state before changes.
- ↩️ Recovery — instant rollback to a saved point.
- 🗑️ Removal — merging changes to the main disk to free up space.
- 🌳 State tree — allows you to create system development branches for different test scenarios.
Typical problems and solutions
Even with proper setup, difficulties can arise. Often, users encounter that the virtual machine does not start and displays an error related to VT-x or AMD-V. This means that virtualization technology is disabled in the motherboard BIOS or blocked by another hypervisor (for example, Hyper-V may conflict with VirtualBox).
Another common problem is poor graphics performance. If the guest OS interface is slow even on a powerful PC, check whether 3D acceleration is enabled in the VM display settings and whether the Guest Additions drivers are installed. Without hardware acceleration, rendering falls on the CPU, which puts a lot of stress on the system.
⚠️ Attention: Never turn off a virtual machine using the host’s “Shutdown” button or by pulling out the power if it is in the process of writing to disk. This may result in file system corruption inside the virtual container.
Network problems are often resolved by resetting the adapter. If the guest OS does not see the network, try changing the connection type to “Network Bridge” and back in the hypervisor menu, or temporarily disable and enable the virtual network adapter in the host device manager.
Why does the time in a virtual machine get lost?
This often happens because the host and guest clocks are out of sync. In the VM settings there is usually an option “Synchronize time with host” that needs to be activated.
FAQ: Frequently asked questions
Do you need a powerful computer to run a virtual machine?
For simple tasks (browsing, office), a modern average PC with 8 GB of RAM is sufficient. For heavy tasks (games, code compilation), it is advisable to have 16-32 GB of RAM and an SSD drive.
Is it possible to run a virtual machine on a virtual machine?
Yes, this technology is called nested virtualization. It requires support from the processor and hypervisor, as well as enabling a special option in the settings.
Is it safe to test viruses in a virtual machine?
Relatively safe if insulation is maintained. However, there are viruses that can “escape” from a VM (VM Escape), although they are rare. Never connect VMs with viruses to the general enterprise network.
Does the virtual machine take up disk space if it is turned off?
Yes, it takes up space equal to the size of the virtual disk (or actual used space if dynamic is selected). The files are stored on the host's physical disk.