Virtualization programs. Some VM and guest system settings. Why do you need a virtual machine?

The concept of virtual machine (from the English. Virtual Machine) understand a software or hardware system that emulates the hardware of a certain platform (guest platform), executing programs for the guest platform using the host platform.

Also, a virtual machine can virtualize a certain platform, creating independent, isolated environments for work on it operating systems and programs.

Virtual machine for Windows 7 - we offer you an overview of popular programs.

To put it simply, a virtual machine provides the opportunity on one real, physical computer, create several virtual computers, install various operating systems, programs, etc. on them.

This technology came to the general public from the world server infrastructure, where virtual machines are used to create maximum server load and reduce equipment downtime.

Virtual machines are used to solve a range of tasks such as:

Optimizing the use of server resources.
Information security, as well as limiting the capabilities of some programs, the so-called sandbox idea.
Research into new computer architecture or software.
Emulation of various computer architectures (for example, to emulate the PlayStation game console from Sony).
Creation malicious code.
For example, the SubVirt rootkit, created in 2006 by Microsoft Research (MSR), created a virtual work environment, which contained the user’s operating system along with an antivirus, firewall and other software designed to protect the PC.
At the same time, the rootkit itself remained external and therefore did not fall within the scope of antiviruses, providing remote control over a virtual machine to an attacker.
Modeling computer networks.
Software testing and debugging.

We bring to your attention a brief overview of the most popular virtualization programs.

Virtual machine for Windows 7: Virtual Box

Virtualization program from Oracle, for operating systems Linux, Mac OS X, MS Windows, etc.

The program is quite popular and below we will consider not everything, but only its key advantages:

Free.

Cross-platform.

Support for 64-bit guests on 32-bit host platforms. To do this, the host platform must support virtualization technology at the processor level.

Audio device support and various types network interaction.

The ability to create a chain of backup states that you can return to in case of problems with the guest system.

Russian-language interface.

Important! The program's shortcomings are not significant, but for the sake of objectivity in the assessment, they should also be mentioned - VirtualBox is poorly compatible with Win 95/98 OS (noted slow work systems) and Mac OS X (sound problems).

As you can see, the program's shortcomings are not significant and are rather nominal.

Virtual machine for Windows 7: Xen

Virtual Machine Monitor (hypervisor), developed at the University of Cambridge and distributed open source source code(GPL license).

Using paravirtualization technology (PV mode), Xen allows you to achieve very high performance by emulating real hardware platforms.

A special feature of the PV mode is the absence of the initial moment of booting the computer (imitation of BIOS code, bootloader) and the guest OS kernel starts immediately in desired mode, like regular programs.

It's worth noting that Xen can be compared to software corporate level due to its rich functionality.

Advantages:

Free.

Cross-platform.

High performance of running virtual machines, which is very close to the performance of real systems.

Ability to migrate running virtual machines between physical hosts.

High degree of support for emulated hardware.

There is perhaps only one drawback of the program - its relative complexity, compared to similar software from other companies.

Virtual machine for Windows 7: Virtual PC

Initially this program was developed by Connetix for Mac OS back in 1997. 4 years later, a version for Windows OS was released.

Later, in 2003, the rights to the program were acquired by Microsoft Corporation, and in 2006 the program became free.

Subsequently, Virtual PC was not developed and currently contains the functionality of 2007.

Advantages:

Free.

Simple, user-friendly interface.

Flaws:

The program only works in Windows OS, but is not compatible with Windows 8 and higher.

The program, unlike Virtual Box, is not compatible with AMD processors.

Virtual machine for Windows 7: VMware Player

A product from the largest American virtualization software developer Vmware.

Vmware products are primarily aimed at the corporate segment of the market, therefore full version programs - VMware Workstation- paid.

The license price is about $250. For non-commercial use, the manufacturer offers a program with limited functionality VMware Player.

It is worth noting that the restrictions generally apply to software developers and IT specialists; the program is quite functional for performing the tasks of the average user.

Advantages:

Free.

Fast.

Simple, user-friendly interface.

ThinPrint technology allows you to print any document opened in the guest OS without installing additional drivers.

Working with multiple monitors in a guest OS.

Exchange files between guest systems using Drag&Drop technology.

Flaws:

Limited functionality free version.

Installing Windows 7 x64 on VirtualBox (virtual machine)

Virtual machine for Windows 7: multiple operating systems on one machine

A Virtual Machine is software environment, which emulates the hardware of a computer with all its components. Essentially, a virtual machine is a separate virtual computer on which operating systems, programs, drivers, etc. can be installed, which can then be run in isolation from the main operating system installed on this computer.

In this article we will look at what a virtual machine is and what it is needed for. Usage virtual machine it happens something like this: you install a special virtualization program (virtual machine) on your computer, into which you can then install one or more operating systems supported by this program.

For example, your computer has the Windows 7 operating system installed, and you want to try another operating system: Windows 8.1, or Windows 10. You are not yet ready to immediately switch to a newer operating system, so by installing Windows 10 on a virtual machine, you can Familiarize yourself with its work and capabilities in detail and gain the necessary skills.

In parallel, you can install other operating systems in the virtual machine: various Linux distributions, Mac OS X, etc. At the same time, you can use Windows 10 on your computer, for example, and Windows 7, Ubuntu, and Mac OS X on a virtual machine.

Most popular programs to create virtual machines (VMs) for ordinary users(there is a large corporate segment of virtualization systems): Oracle VirtualBox(free), VMware (free for personal use VMware Player, paid VMware Workstation), Parallels (for computers with Mac OS X), Windows Virtual PC (Windows 7 starting with Pro edition, supported free installation virtual Windows environment XP Mode), Hyper-V (works in x64 bit Windows versions, starting with Windows 8) and others.

Virtual machines different manufacturers differ in their capabilities and features. It will be possible to download virtual machines from the websites of software manufacturers.

Using virtual machines

Virtual machines (VMs) are mainly used for the following purposes:

installing another operating system to study or work with
testing unfamiliar programs without risk to the main operating system
using programs that cannot run on your computer
setting up a local network
Safely launch suspicious applications
simultaneous installation of several operating systems on a computer

For example, on my computer in different time, were installed in virtual environment the following operating systems: Windows XP, Windows 7, Windows 8.1, Windows 10, Mac OS X, Linux Mint,Android.

Working in an operating system installed in a virtual machine is no different from working in normal system installed on your computer. This is a regular OS running in a virtual environment. You can do whatever you want without fear of killing Windows or another system. If as a result of your actions the OS becomes inoperable, then you can simply remove this operating system and install another one instead.

Many virtual machines have the ability to create a snapshot of the system, so you can easily restore a “dead” OS.

Most likely, powerful, resource-intensive games will not run on a virtual machine, because such games will most likely slow down greatly. The performance of the operating system installed on a virtual machine depends on the power of the specific computer.

In this image you can see that Windows 10 is installed on my computer, and in the virtual machine window (I deliberately made the virtualization program window smaller) the Windows 8.1 operating system is running. Thus, at that moment, two different operating systems were running simultaneously on my computer, independently of each other.

The operating system installed in the virtual machine will run in isolation from the main operating system installed on your computer. You can do whatever you want with Windows (or another operating system) installed in a virtual machine. The main system installed on your computer will not be affected by running in the virtual machine, or by other changes made to the operating system installed on the virtual machine.

You can test unfamiliar programs on a virtual machine before installing them on a real system. Windows OS, or another operating system (if it is not free), will need to be activated.

Some programs do not run on a particular operating system, so you can install such a program on a supported operating system in a virtual machine. In this case, you can continue to use the required application on your computer.

A virtual machine can be used for security purposes. For example, you may not immediately install a program on your computer that makes you suspicious, but will first install such a program on a virtual machine. If your suspicions are confirmed, the main operating system installed on your computer will not be affected in any way.

You can safely visit suspicious sites, risking only the guest system installed in the VM.

In this image, the virtual machine is running the Mac OS X operating system, in the window of which Safari browser. In VMware Workstation guest the system can be expanded to fill the entire screen of your computer monitor.

When using a virtual machine, along with the advantages, there are also some disadvantages. The main problem: on low-power computers, work in a guest system installed on a virtual machine may slow down (freeze, slow down). This is due to the fact that at this time the resources of your computer are simultaneously consumed by two operating systems: the main operating system installed on your computer and the guest operating system installed in the virtual machine.

In order not to overload your computer, I recommend, while working in the guest operating system, to close unnecessary items in the main system. this moment, applications. After this, the load on your computer’s resources will decrease somewhat, and working in the guest OS installed on the virtual machine will become more comfortable. On powerful computers similar problems, usually do not arise.

If you want to try another Windows operating system on your computer, but due to the low power of the computer, working in a virtual machine will be difficult, then you can install another system on the virtual HDD(VHD). You can read more about this. With this option, you will launch operating systems on your computer one by one.

When working with a virtual machine, you can easily remove any operating system from there without any consequences for your computer, and also remove the virtual machine program from your computer.

Conclusions of the article

By using special program: virtual machine (Virtual Machine), you can install another operating system on your computer to familiarize yourself with its operation, to test applications, solve compatibility problems, for security purposes, etc. You can try several different virtual machines and stop on the most convenient option for you.

What is a virtual machine and what is it for?

A virtual machine is a program that allows you to emulate a real computer with all its components (BIOS, hard drive, drive, etc.). You can install any operating system, as well as programs and drivers, on this virtual PC. You can seamlessly exchange data between your real system and the virtual one.

I won’t say that absolutely every user needs a virtual machine, but an advanced user often needs one. A virtual machine is used for various purposes and tasks:

To install another or second same OS;
For testing various software;
To emulate a computer network;
To run applications that cannot be launched from your OS.

If you bring specific example, then, for example, Windows XP is installed on your PC, and you can install Windows 7, Windows 8 or Linux on a virtual PC.

In this article I will talk about three popular emulators, their main features and the advantages of each of them. I'll present it as a bonus Android emulator for Windows and will give an example of creating a virtual machine using one of the emulators.

VMware is one of the most famous and widespread virtual machines. It is usually used by large corporations. VMware is presented in two forms: Player and Workstation, the first of which is free, and the second is paid.

VMware also supports 32 and 64 bit systems, as well as USB 3.0 and various operating systems.

Key Features:

VMware allows you to connect USB devices, CD/DVD drives, network interfaces and others;
Supports moving and copying files using drag and drop;
You can connect new virtual machines using a step-by-step wizard;
You can create a virtual machine using the installation disk or from a ready-made disk image;
VMware Player supports virtual machines that were created on paid VMware.

Microsoft Virtual PC

Microsoft Virtual PC is a free virtual machine with user-friendly interface and great functionality. The only small drawback is that only Windows operating systems are supported.

Main features:

It is possible to select the equipment that is needed on the virtual machine;
You can add or remove hardware on a virtual computer;
You can copy virtual machines;
I have an opportunity fast switching between virtual PCs using bookmarks;
It is possible to drag and drop files from the main PC to the virtual one and vice versa;
You can connect virtual and real computers over the network.

VirtualBox

VirtualBox is a free emulator on which you can install the most popular operating systems, such as Windows, Linux, FreeBSD, Mac OS. Supports both 32 and 64 bit versions operating systems. Also, VirtualBox can work with virtual computers that were created in a paid VMware program Workstation.

Main features of the program:

VirtualBox can be controlled via GUI, and through the command line;
VirtualBox makes it possible to connect USB devices to virtual computers and allow them to work with them directly;
All virtual machine parameters are described in XML format and therefore do not depend in any way on the physical PC on which the system runs;
VirtualBox supports remote control;
Exists special package SDK for expanding program functions.

After analyzing the reviews of all three emulators, we can come to the conclusion that VirtualBox is the most suitable program to create and manage virtual machines. Therefore, we will look at installing a virtual machine using VirtualBox as an example.

Installing a VirtualBox virtual machine

Let's look at how to install VirtualBox, and in the next chapter we'll see how to configure it.
Download the latest version of the program from the official website or from our Download program
We launch the installation and see the first welcome window. Click “Next” and move on to the next stage.

At the second stage of installation, we see the program components that will be installed and the directory into which the program will be installed. The installation directory can be changed, but it is recommended to install all components. Even if not all components are needed right now, but they will be needed in the future, you will need to reinstall the virtual machine.

At the next stage, a warning appears about the computer being temporarily disconnected from the network during installation.

A window will then appear informing you that you can begin installation. Click the “Install” button and wait for the installation to complete.

During the installation process, pop-ups may appear that say “Install software for of this device? Click the “Install” button.
When the installation is complete, click the “Finish” button. The virtual machine will automatically start after installation is complete.

Creating a VirtualBox virtual machine

In order to create a virtual machine you need to in the window VirtualBox programs click on the “Create” button on the left top corner.

At the first stage, enter the name the machine being created and select the type of operating system. For example, let's create a virtual machine with the Windows 7 operating system. Let's move on.

At the second stage we set the quantity random access memory, which is required for the virtual machine. We install based on the needs of the selected operating system. IN system requirements Windows 7 states that it requires at least 1 GB of RAM. Let's indicate, for example, 1.5 GB. Here you need to take into account that you cannot install more than half of the RAM of a physical computer in a virtual machine.

Now you can connect a virtual hard disk to the created virtual machine. First we create it. Select “Create a new virtual hard disk” and click on the “Create” button.

We indicate hard type disk. If you are not familiar with the formats described there, you can leave it as is and click “Next”.

Now you need to specify the format for storing data on the virtual hard disk. A dynamic virtual hard disk can expand, while a fixed one has a strictly defined size. Choose what you like best.

Specify the name of the virtual hard drive and its size. Click “Create”.

Setting up a VirtualBox virtual machine

Let's see what settings the virtual machine has. Click the “Configure” button in the upper left corner of the program.
The settings window appears. Here you can change various parameters virtual machine (for example, the amount of allocated RAM, enabling 2D acceleration, device boot order, etc.)
All settings are divided into categories.

If you make a mistake in the settings, the program will inform you about this by appearing at the bottom of the settings window the inscription “Incorrect settings detected.”

Usually the first 3 categories of settings are enough for the user. If the virtual machine is running slowly, you can increase the amount of RAM or use more processor power.

Having completed the settings, click the “OK” button. To start (enable) the created virtual machine, click on the “Launch” button. Now we insert it into the drive installation disk with the operating system, install and configure the operating system and your virtual computer is ready for use.

That's all, we looked at 3 popular emulators and identified all of them strengths, chose the most suitable one for us, installed and configured the virtual VirtualBox machine, and now the promised Bonus.

BlueStacks - Android emulator for Windows

BlueStacks Player is a program that allows you to run Android applications on a computer running Windows or MacOS. BlueStacks allows you not only to get acquainted with Android capabilities, but also to fully test applications created for this operating system. Using an emulator BlueStacks users will be able to install and run on their PC any of the numerous programs available in Google Play, GetJar, Amazon Appstore, 1Mobile and other online catalogs of Android applications. The best part is, BlueStacks is completely free.

Key features of BlueStacks

Most important feature BlueStacks emulator supports LayerCake technology, which simulates ARM processor. This technology allows Android applications run on x86 processors. It is also imitated graphics subsystem ARM, which makes it possible to perform the most modern games, which are written for Android tablets. The actions of moving pages with your fingers, which tablet users are used to, are performed on BlueStacks with the mouse.

Unlike other virtual machines, you don’t need to install the operating system manually on BlueStacks - everything Android features available immediately after launch. One tweak you need to make is to change the interface language. Russian language is fully supported.
BlueStacks works on Windows 7, Windows Vista, Windows XP.

This concludes our review for today. Good luck with the emulation.

To have several operating systems with separate workspace and applications at hand, you don’t need to buy a second (third, fourth, etc.) computer. Because it all fits into your single PC. How? Thanks to virtual machines (VMs) - special programs that create (emulate) imaginary (virtual) computers inside the main operating system.

A virtual PC is almost like a real one. It has its own processor, memory, hard drive, network adapter And all the rest. Of course, these are not physical devices, but they are made in such a way that operating systems consider them to be just that - real.

Several virtual computers can work simultaneously on one physical computer. Exactly how much depends on the hardware resources: the faster the processor, the larger the RAM, the more spacious the storage, the more. A typical home PC with average performance Windows based 10 copes with the simultaneous operation of three to five lightweight operating systems (for example, Windows XP, Android and Lubuntu + the main system). Or two or three relatively heavy ones (for example, the main Windows 10 + virtual Windows 7 and Mac OS X). As you already understand, virtual computer emulator applications allow you to install and run a variety of operating systems on them.

Virtual machines general purpose(as opposed to specialized ones, such as, for example, VM Java), use:

To run applications that the main system does not support.
To protect the system from potential harm from untested programs.
As an additional barrier against viruses when visiting dubious web resources.
For creating isolated environment to study the activities of malware.
As a testing ground for debugging your own developments.
To master network construction technologies.
For double authorization on some gaming portals and much more.

And of course, virtual machines are widely used to distribute server work resources.

Today we will not touch on the industrial use of VMs, but will only consider what can be useful to home users of Windows OS.

Oracle Virtualbox

Let's look at the process of creating a new virtual machine and starting to install Windows 10 on it.

Click on top panel"Create" button.

In the first window of the VM creation wizard, we will indicate the name of the OS (it will be displayed in the list of guest systems), its type (Windows, Linux, etc.) and version. In our example, this is Windows 10 32 bit (you can install 64 bit, but it will require more resources). To go to next step Click Next.

Next, we will indicate the size of the VM RAM. By Windows default 10 x86 is allocated 1 GB, but you can increase this amount by moving the slider to the right. If your PC does not have a lot of RAM, do not give the VM more than 2-3 GB, otherwise the main system will slow down due to lack of memory.

Next we create a virtual hard disk. If you are installing the system for the first time, select the “Create new” option.

Type virtual disk Let's leave it as default.

Data storage format is an area on physical storage your computer, which is allocated to the VM. It can have a constant or dynamically expanding volume within the limits that you define further. To save space, we will choose a dynamic format.

Next we indicate the name of the volume (virtual disk C) and its size. The default is 32 GB.

After clicking the “Create” button in the last window, a new virtual machine will appear in the list. Its parameters are shown in the frame on the right.
To go to Windows installation Click the “Run” button in the top panel.

In the window that opens after this, the “Select boot disk" Click on the folder icon and specify the path to the system distribution. This can be an image in .iso format or physical media(DVD, flash drive). After selecting your distribution, click Continue.

The further course of installing the OS into a virtual machine is no different from installing it on a physical computer.

Some VM and guest system settings

Clicking on the virtual machine window will lock the mouse cursor (i.e. it will only move within virtual screen). To return the cursor to the main OS, press the Ctrl+Alt combination.

To access the full range of features of the guest OS, you need to install special add-ons. Go to the "Devices" menu, click "Mount Guest Additions Disk Image" and follow the further instructions.

To connect a folder to the guest system for exchanging files with the main one, click the “Shared Folders” item in the “Devices” menu. Click on the “folder+” icon in the window that opens and use the “path to folder” field to specify it in Explorer (it shows the directories of the main system).

If you want the setting to work constantly, check “Auto-connection” and “Create permanent folder». a shared folder will be available from the virtual machine explorer as a network one.

To change the poll order boot devices(for example, to boot a virtual machine from DVD), shut down the guest OS, open its settings (in the main Virtualbox window) and go to the first tab of the “System” section. In the "Load Order" list, select the desired media and press the arrow buttons to move it to the top.

VMware Workstation Pro

Some Hyper-V virtual machine options

To take a snapshot of the running guest OS, Open Top Menu its "Action" window and click " Check Point" Or press the combination Ctrl+N.

Access to the settings of an individual virtual machine is available from its context menu in the list of the main manager window and is hidden behind the “Options” button.

Other features of the program are also very simple and can be mastered without much difficulty.

Virtualization allows you to encapsulate internal organization operating systems or parts thereof within virtual hardware and software. In other words, create a virtual space that will be real from the point of view of the operating system running in this space. This is exactly what virtual machines do for Windows 7, Linux and Mac OS X. Virtualization also allows you to simulate devices that are not even on your computer.

Note: In a sense, virtual machines allow you to create a computer within a computer.

There are two important aspects machine virtualization:

interaction between a physical host (computer) and a virtual host
interaction between the operating system running in virtual space, and the equipment used

Virtualization software, namely virtual machines for Windows 7 (Linux, Mac OS X), as a rule, is normal application or an operating system service that allows you to create hosts. Any host is called physical machine(computer). Within virtualization software, the operating system runs on a host similar or identical to the actual host, called a virtual machine. For convenience, the operating system running in a virtual machine is called a guest operating system.

In addition, there are various ways virtualization, on which not only the implementation of applications for creating virtual machines depends, but also the capabilities provided for guest systems. There is regular emulation, in which hardware and program calls pass through the intermediate layer. There is also para-virtualization, where part of the actions inside the virtual machine takes place on real hardware, while the other part passes through an intermediate layer. There is also virtualization at the system level, when each guest system boots in a special kernel, which allows you to run only similar versions of the operating system.

Some of these methods can be performed on the fly, without significant changes to the actual host and its operating system. Others require the host to be rebooted into a special instance of the operating system that supports virtualization. Others use special hosts that support and are designed for virtualization at the hardware device level. The latter are also known as bare metal virtualization methods (although this is not entirely true, since some software kernel is still used).

The virtualization software that manages the creation and operation of virtual machines, as well as the allocation and limitation of the resources provided, is often called a hypervisor. Some virtualization applications can also use special processor extensions to improve the performance of virtual machines. The presence of such extensions is called hardware support for virtualization. Examples of this support are VT-X (Intel) and AMD-V (AMD) technologies.

What is not virtualization and virtual machine?

Some people like to call virtualization programs (virtual machines) anything that creates a layer of abstraction between the operating system and some of the running processes. For example, there is Sandboxie, which allows you to isolate browsers from the system (see browser protection utilities). Some programs allow you to freeze the state of the system so that it cannot be changed. Others also allow you to use the so-called shadow mode, in which all programs run normally, but any changes are canceled when you restart the computer.

Of course, all of these programs provide various benefits, but they are not considered virtualization technologies and are not virtual machines because they do not simulate system calls, and they do not allow guest operating systems to run on top of the current system. Such programs only create additional layers of separation, mainly to increase the level of security. If we continue the topic of security, then...

Why use virtualization and virtual machines?

If security comes first for you and is the first thing you think about in any situation, then virtualization (the use of virtual machines) can certainly help you with this. But don’t assume that virtualization is mainly used for security. Its initial goals are: testing, cost reduction, flexibility, legacy product support, and education. Increasing the level of security is just a pleasant bonus, which also has many pitfalls.

Note: Although virtualization allows you to isolate one operating system from another, there are still ways to get from the guest system to the main one.

What is needed to run virtualization technology and virtual machines?

The first thing to consider is the physical host. Depending on the type of virtualization software (virtual machines), you may need completely miscellaneous equipment and various operating systems. Virtualization does not imply any single solution that will run wherever needed. Virtual machines need to be selected for the system (Windows, Linux, Mac) and for the hardware (hardware). In addition, the host must have the necessary .

So if you are going to run guest operating systems on top of your system, you will need additional resources to run them, such as the processor and RAM. For example, if your computer only has 2 GB of RAM and you want to run a guest system on Windows 7, then you will have to severely limit resource usage on real system so that the virtual machine can function normally. Unless, of course, you're trying to run Windows XP with 256 MB of memory. However, if you have 16 GB of RAM, then you can run more than one guest system without experiencing any shortage of resources.

Pros: Easy to install and use.

Cons: Limited functionality. Does not support snapshots and general access to catalogs.

Virtual machine for Windows 7, Linux and Mac OS X - VirtualBox

VirtualBox is another cross-platform virtual machine creation program for Windows 7 and above, as well as Linux and Mac systems, currently owned by Oracle. VirtualBox is similar to VMware Player, but has more features, including more advanced network stack, unlimited amount snapshots, some support for OpenGL and DirectX, and much more. The app is easy to install and just as easy to use. You can also use the command line for automatic deployment. VirtualBox also supports USB and shared directories. In addition, there is portable version VirtualBox. However, there are also disadvantages. You cannot take screenshots of guest systems. Disk management is a bit confusing.

Audience: beginners and experienced users.

Pros: Easy to install and use, many features.

Cons: No support for screenshots, import existing machines complicated, non-intuitive disk management.

VMware ESXi hypervisor for creating virtual machines

ESXi is a bare metal hypervisor with reduced functionality compared to ESX. The app requires a host and can be controlled from the console (the console is locked by default, but you can enable it manually). You will not be able to take screenshots or record video of the screen of your virtual machines. Transferring and cloning guest systems can only be done manually. But you succeed sharing memory for increased efficiency use of RAM, powerful monitoring and management, and command line access via SSH (when unlocked). You can also install VMware Tools to improve the performance of virtual machines. Para-virtualization is also supported by ESXi.

Pros: Powerful, advanced virtual machine capabilities.

Cons: Requires a host and a lot of resources. Not easy to install and run.

Virtual machine for Unix/Linux - Kernel-based Virtual Machine (KVM)

KVM supports virtualization only for UNIX-like operating systems (Linux). The application can be run on any hardware or in emulation mode, but without processor extensions the performance will be terrible. KVM is designed to be used via a console. But, it has a decent management interface that allows you to start and stop virtual machines, take screenshots and much more. The interface is known as the Virtual Machine Manager (VMM) and is also used to manage Xen virtual machines (see below). Local and remote control. There is a known conflict with VirtualBox, but it can be resolved relatively easily

Audience: advanced users and professionals.

Pros: Full control and flexibility is very high performance, under appropriate conditions.

Cons: Only UNIX-like systems. Requires hardware virtualization extensions for normal execution. Emphasis on the command line. Not easy to install and run.

Virtual machine for Unix/Linux - Xen

Xen is another application for virtualizing UNIX-like operating systems (Linux). It must boot in its own kernel instance. The emphasis is on the command line. But, you can also use VMM. Officially, Xen has been supported by OpenSUSE for many years and was recently added to the main kernel release branch. Xen can run in hardware-assisted or para-virtualization mode. However, for para-virtualization, Xen is extremely problematic to install and run. Additionally, Xen has limited CD-ROM support and network devices. The program is also available as a bare metal virtualization hypervisor on a Live CD. There are numerous third party extensions for managing Xen.

Audience: advanced users and professionals.

Pros: Full control and flexibility, very good performance, native kernel support.

Cons: UNIX-like systems only. Para-virtualization mode is buggy. Emphasis on the command line. Several utilities command line which may be misleading. Not easy to install and run. You must boot your own instance of the kernel.

A few words about virtualization programs

This review will be useful not only for novice users, but also for experts. The listed products cover a wide range of virtualization technologies at all levels. All solutions described are free for personal use. Choose what you want or need based on what you have hardware, requirements for ease of setup and launch, as well as the availability required set functions.

Typically, most people start learning virtualization with VMware Player or VirtualBox. Linux users may prefer KVM and perhaps Xen. Advanced users might want to take a look at ESXi.