Comparison of virtual machines for windows. Virtual Machines Overview

Fast:

When choosing a desktop virtualization platform today, users essentially have only two choices - VMware Workstation and Oracle VirtualBox. The remaining analogues of desktop products have either already been discontinued or frankly do not reach the functionality of these two platforms.

At the same time, VMware Workstation is a full-fledged commercial product with closed source code (the source code is open only for VMware Player - a stripped-down version of Workstation), and Oracle VirtualBox is a platform that runs on top of many operating systems (VirtualBox OSE edition is open source).

We will not touch on performance issues here - they were discussed earlier and, but these reviews are no longer relevant. In general, according to user reviews, both products show more or less the same performance in average conditions (although there is an opinion that VirtualBox is faster). This note provides a comparison of and.

What VirtualBox and VMware Workstation platforms are both good at:

• Clear graphical interface
• Convenient network interaction editor on the host
• Virtual machine disks that grow as they are filled with data (Thin Provisioning)
• Instant snapshot technology
• Application technology in the host OS from the guest OS in seamless windows (that is, the application from the virtual machine is “moved” into the workspace of the host system, as if it were running there)
• Supports a large number of guest OSes, supports Windows and Linux as guest OSs
• Support for 64-bit guest OS
• Intel VT and AMD-V support
• USB 2.0 devices in virtual machines
• Play audio on host devices from a virtual machine
• Clipboard between guest and host OS
• 3D graphics support for games and other applications
• Support for importing virtual appliances (Virtual Appliances)
• Improved guest OS drivers: VMware Tools and VirtualBox Guest Additions (both packages update automatically)
• Both platforms support Memory Overcommit techniques (the so-called Memory Ballooning - redistribution of free physical memory between guest operating systems of virtual machines)
• Both platforms support multiprocessor virtual machines (at least 8 vCPUs)
• Expanding virtual disks (more convenient in Workstation)
• Copying files between a virtual machine and the host OS
• Both platforms have support for accessing the virtual machine console via an RDP server

Why choose VirtualBox over VMware Workstation:

• VirtualBox is absolutely free, and VMware Workstaion costs $207.90 according to the Russian price list as of March 2011 (if you purchase less than 10 licenses).
• VMware Workstation runs only on Windows and Linux host OSes, while VirtualBox supports Windows, Linux, Mac OS X and Solaris hosts.
• "Teleportation" technology, which allows you to move a running virtual machine to another VirtualBox host without having to stop it. This feature is not available in VMware Workstation
• VirtualBox has the ability to work not only with the native .VDI format, but also .VMDK and .VHD. VMware Workstation only has the ability to run virtual machines from VMDK virtual disk images (although there is a free product called VMware Converter for importing virtual machines from other formats).
• VirtualBox has more options for working from the command line (managing VMs, devices, snapshots and much more)
• VirtualBox has better audio support for Linux hosts (Workstation disables audio in the host OS, VirtualBox can play in parallel)
• VirtualBox has the ability to limit CPU and I/O resource consumption, VMware Workstation does not have this (only VMware vSphere can do this)
• VirtualBox has the ability to adjust video memory

Why you might choose VMware Workstation over VirtualBox:

• VMware Workstation is a commercial product, which means you can always count on support with a certain SLA level
• VMware Workstation has more features to support 3D graphics, such as: Windows Aero user interface, OpenGL 2.1 and Shader Model 3.0. The 3D acceleration itself works more consistently than in VirtualBox.
• VMware Workstation has a universal print driver. ThinPrint (no need to install drivers in the guest OS)
• Creating snapshots at specified time intervals (), which allows you to protect virtual machines similar to the autosave feature (for example, like in Microsoft Word).
• Compact Virtual Disks - compression of virtual disks to serve the needs of other systems.
• VMware Workstation has wider functionality for working with virtual network interaction - switches, DHCP, NAT, etc. (although VirtualBox also has NAT, Bridge Networking - in Workstation this is subjectively more convenient).
• VMware Workstation has Linked Clones functionality for virtual machines.
• Recording the activity of a virtual machine in video format, as well as in the form of a sequence of user actions (Guest Record / Replay).
• Workstation has the ability to integrate with development and testing environments (for example, Eclipse), as well as specialized functions for software developers (but VirtualBox has a cooler API).
• Protect virtual machines with 256-bit encryption
• Workstation has several nice little things - like shortcuts to applications from the Start menu, Pause a Virtual Machine (not suspend), etc.

In general, if you don’t know why exactly you need VMware Workstation, then feel free to choose the free VirtualBox. If you are a software developer or testing engineer, then I recommend choosing VMware Workstation, which has many convenient little things that you use every day that are missing in VirtualBox.

Colleagues, if you notice any error in the comparison of functionality or you have something to add to this comparison, please write about it in the comments.

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Which one do you think is the best?

I will not invent a story and retell others. I’d rather suggest you read an article from Linux Format magazine. In which experts made a comparative review of five popular virtual machines in the hope of finding the one... the best virtual machine. By the way, I highly recommend that those who renounced and were able to escape from the captivity of Windows subscribe to the magazine.

• What is a virtual machine
• Why do you need a virtual machine?
• How we tested Virtual Machines
• Performance
• Functionality
• Compatibility and snapshots
• Desktop integration
• Graphics acceleration
• Verdict

What is a virtual machine

In simple terms, without getting bore, a virtual machine is an operating system within an operating system.

Why do I need a virtual machine

In our case, a virtual machine is primarily a platform for testing programs. Among which, as you understand, there may be . The virtual machine is also used by hackers to test their own and other people’s Trojans and other miracle files. No matter what group you belong to, you will still be interested in learning more about virtual machines and how they work.

How we tested virtual machines

First, we took a dual-core computer (due to budget restrictions) with fresh Arc Linux. In addition to proprietary VMware (version 7.1.0 of Layer and a 30-day trial of Workstation 11), we used the official Arch packages, which follow developer releases very closely. Each machine had 2 GB of system RAM and 128 MB of video memory (256 MB if needed).

We tested each candidate on different guest OSes: Mint 17.1 and Kubuntu 15.04 beta, as well as different versions of a non-Linux OS called Windows. To evaluate performance, we compiled the core Mint core, ran the SunSpider JavaScript benchmark, and played various games from our Steam library. To test the real world, we ran it on an 8-core machine with 16GB of RAM and a 4GB Nvidia GTX, but then we were forced to return it.

Virtualization technology has fundamentally changed the computing landscape. We'd be embarrassed to say that this is a new invention (early mainframes used it as a means of provisioning), but decade-old CPU innovations mean that you'll only get near-native performance with x86 code. And now we manage to cram dozens of machines (easily copied and restored) into one case, and the work of data centers has become much more efficient. You can also imitate another architecture, say, ARM, which is convenient for embedded system developers.

This is also a benefit for ordinary users: getting to know a new OS no longer has to be such a time-consuming exercise in constant fear of ruining your system. Even if you just want to test out a new program, it's much safer to do it in a virtual machine instead of risking your current setup. Support for in-kernel virtualization (via KVM) and the Qemu emulator means Linux users no longer need to resort to proprietary tools.

In the old days, VirtualBox from Sun (once owned by Innotek, now Oracle) was the only real option. But times have changed, so let's look at other virtualization applications.

Both VMware and VirtualBox use kernel-dependent modules that are loaded to work their magic. VMware will need to compile them, which will require installing the kernel header packages and all the compiler stuff. You will then receive an init script to load the specified modules, although this will be of no use to Systemd users. If this is your case, you might want to create your own init file instead of running this script as root all the time (or seeing the same error messages). At the time of writing, the 3.19 series kernels required patching up the VMware source code, but hopefully this will be fixed by the time the magazine is published. VirtualBox packages are available in most distributions, and if you have a standard kernel, you don't have to worry about anything.

Virt-Manager requires the libvirtd service to be running on your system before it can be launched, which a helpful message will notify you of, and if you're using a full-featured desktop environment, it will do this for you; All you have to do is enter the root password.

Both VirtualBox and VMware Workstation are quite simple, as long as you don't get distracted by each option. But in VMware Player there are not so many options, and you will get your machine up and running very quickly. But if you're determined to make the most of all these options, you'll have to install the Guest Additions.

The Linux Guest Additions for VirtualBox are much easier to install (the CD will run automatically) than the VMware add-ons, which require you to copy programs from an imaginary CD, change the permissions, and then run the script. Is it really 1999? But, having done all this, you will be rewarded with improved graphics and a number of additional functions, which we will discuss further.

The easiest to use of our selection is Boxes, even if this is due to providing only the bare minimum of Qemu / libvirt functions. VMware Player and VirtualBox come in second, followed by their paid rival (nominally more difficult, due to more options). Virt-Manager isn't particularly difficult to use, but it has just enough of Qemu's maze of settings to overwhelm a newbie. In addition, its mechanism for managing storage is quite confusing, especially if you are going to store your virtual disk in a non-standard location: then you first need to add the required directory as a “storage pool”. However, all the necessary exotic modules will be provided by your own distribution, and in this case, why not take a risk.

Performance

Will they create a slow or agile VM for you?

Thanks to hardware enhancements and paravirtualization technologies, it is now possible to perform some tasks at speeds close to those of real hardware.

However, as it is, there is usually some performance hit. Almost every configuration on which we tested the guest desktop exhibited some kind of slowdown. But you get used to it, and you can turn off all the beauties or turn on the appropriate troubleshooting mode if it bothers you.

We're not taking 3D performance into account here - that wouldn't be entirely fair, and it has its own category across the page. However, for everyday tasks using Terminal, you're unlikely to notice much difference between our candidates. Experiments with kernel compilation have shown that VirtualBox is significantly behind the competition. SunSpider's JavaScript benchmark test confirmed this finding, with both tasks running 20% ​​slower than the others. Disk input/output (I/O) (especially if you have an SSD) and network traffic were fast for all of our candidates. Ultimately, VMware gained an edge by supporting newer Intel processors.

Functionality

What does each candidate have to offer?

All of our candidates target different use cases and therefore each have their own, individual benefits. Of course, the presence of some standard features is certainly implied: these, for example, include the ability to create snapshots, support for Intel VT-x and AMD-V processor extensions, and flexible configuration of virtual hardware. All this is offered by everyone, but some applications are capable of more heroic feats.

A disclaimer here is that Gnome Boxes and Virt-Manager are just interfaces to Qemu (via the libvirt abstraction layer). And Qemu is essentially a processor emulator that is capable of virtualization via KVM, but is still a world of its own.

So, let's look at our candidates individually.

Gnome Boxes ★★

When invoked from the command line, Qemu supports a ton of options, most of which are missing from Gnome Boxes: its goal (implemented) is to be simple and straightforward in appearance and operation. Through its user-friendly wizard interface, you can set up a virtual machine in literally three clicks - just point it to the appropriate ISO. Boxes abstracts the difference between a virtual machine and a remote machine, and you can connect to both via VNC, SPICE (which allows audio to work over a network), or OVirt.

Gnome Boxes

Boxes doesn't offer much in the way of managing your virtual machine over the network, but it at least provides all the NAT wizardry you need to get your virtual machine talking to the world. The remaining candidates successfully configure NAT, network bridges or host-only networks, and all this can be very convenient in certain circumstances.

Virt-Manager ★★★★

Virt-Manager (aka Virtual Machine Manager) offers significantly more Qemu features (but again, not all). It seems to have gone overboard with its list of supported x86 operating systems, particularly those from the Linux family.

Virt-Manager

Leaving this aside, Virt-Manager makes it relatively easy to configure a machine of any complexity - you can add any equipment, including several network interfaces. In addition to KVM VMs, Virt-Man-ager can enable Qemu/libvirt support for Xen guests and LXC containers. Optionally, it can also poll guest resources and thus provide very nice graphs (like the ones in the Performance section on page 25, which take about 30 seconds after Windows 10 starts). Additionally, Virt-Manager takes advantage of Qemu's recently added USB 3.0 support.

Compatibility and snapshots

Is it possible to move virtual machines between real ones?

Sometimes you need to move a VM between hypervisors. All of our programs can import machines stored in the Open Virtual Appliance (OVA) format, which is simply a tarball of a VMDK (VMware) disk image, and virtual hardware data. VirtualBox allows export to this format, but also has its own - Virtual Disk Image (VDI), and also copes with all the others.

The qemu-img command can be used to convert formats. Of particular note is his favorite QCOW2 format, which allows you to store multiple snapshots of the system internally, using the excellent Copy On Write (COW) technique.

Boxes, Virt-Manager, VirtualBox and VMware Workstation support system snapshots, saving different states of their VM. VMware Player only allows you to have one snapshot per machine in addition to its current state. So deep regression testing is excluded.

VirtualBox and VMware Workstation can also "clone" a VM, and this is an effective method of creating system snapshots: data is written to the corresponding clone only if its state is different from the state of the parent. VMware allows you to mount a guest VMDK image on the host, which can also be convenient, although the same trick can be done by converting to a raw disk image and using standard Linux tools and arithmetic to calculate the partition offset.

VirtualBox ★★★★

Originally a desktop virtualization client, VirtualBox is still probably the go-to tool for many. This program has a clear structure that simplifies setting up a virtual machine, and many useful options. In addition to limiting the number of CPU cores that the guest OS has access to, VirtualBox allows you to specify a limit on the guest's CPU usage as a percentage. VirtualBox also supports video recording, so you can record a Windows tutorial for your YouTube channel in an evening.

VirtualBox

It can import any virtual disks, but only offers USB 2.0 host controller support, and then only if you install Oracle's proprietary extension pack. Options for distributed clipboard access and drag-and-drop (in one or both directions, as you wish) are quite convenient. VirtualBox has convenient indicators for network and disk I/O and CPU usage.

By the way, in the article “” we talked in detail about how to install and properly configure the VirtualBox virtual machine.

VMware Player ★★★

VMware's free offering has come a long way since its introduction in 2008. The most remarkable thing is that this is no longer a player: it is more than capable of creating a high-quality virtual machine for you.

VMware Player

In addition to supporting a number of network configurations (NAT, bridged, host-only, etc.), it offers very nice network traffic shaping options, which is quite useful if you are testing the latest version of, say, a DDoS client or seeing how much malware you can hang Windows XP on your virtual machine until it crashes. VMware also supports USB 3.0 devices, and installing guest tools will allow you to use brilliant graphics, a distributed clipboard, and distributed directories. Player is somewhat inferior when it comes to snapshots (it only allows you to take one), but we criticized it in the previous section.

VMware Workstation ★★★★★

There is a non-free version of VMware Player (VMware Player Pro), but we decided that for this Comparison it would be more appropriate to take the higher-end Workstation instead. The app has a lot of extra features for developers, including the ability to group virtual machines into a sort of virtual phalanx so you can have them all come online at the same time with a single click.

VMware Workstation also offers support for new commands on modern Intel processors, and also allows you to configure machines with virtual CPUs, up to 16 and 64 GB of RAM. However, Workstation is very much aimed at integrating with the rest of the (rather heavy) VMware suite, and therefore will look more at home in an enterprise environment.

Desktop integration

Will they clash with your color scheme?

Some users love the perfect harmony of the interfaces of virtual machines and their corresponding hypervisors with the host desktop, while others are just confused.

VirtualBox uses Qt4, which is especially infuriating on the Qt-based Arch Linux desktop, which uses Qt5 everywhere, but it's just something of a niche flaw. Boxes fits perfectly with Gnome 3, as you'd expect; Virt-Manager and VMware use GTK3 and also work perfectly with it.

All of our candidates allow us to switch the virtual machine to full-screen mode, and fortunately they all allowed us to switch back using the appropriate key combination.

Standout modes include Unity in VMware (no, this is not a way to make everything Ubuntu-like) and Seamless in Virtual-Box - both display application windows directly from the guest on the host desktop. This is very good for a Linux VM (eliminating the potential confusion between guest and host windows), however trying to run
the preview didn't go well; Windows 7 with Aero enabled was also not the most pleasant experience.

All of our candidates support running the guest in full screen mode, and can be configured to change resolution when the window size is changed. Suitable hotkeys are provided to exit this scenario. The drag-and-drop feature on VMware machines is very convenient, which is why VMware wins in this category.

Graphics acceleration

Is it possible to avoid software rendering problems?

Any of our candidates would serve you well if you just wanted to install a virtual machine with no intention of doing anything graphics-intensive.

But if you need 3D acceleration, you need to use VMware or VirtualBox. Once you get past installing the Guest Additions (including the double-negative VirtualBox question that tries to steer you away from its experimental WDDM support needed for, say, the Windows 7 Aero interface), you'll be able to enjoy 3D acceleration in VirtualBox and in two VMware clients.

Boom-boom, Maxwell's silver hammer landed on the, uh, beehive. He died shortly after this screenshot was taken in Don't Starve.

VirtualBox allows you to allocate up to 256 MB of system RAM to the virtual video card, and VMware - up to 2 GB. Note that these gigabytes are not taken from your actual graphics card, so you often won't see much improvement above 256 MB. VirtualBox also provides 2D acceleration for Windows guests, which should help speed up video rendering, screen enlargement, and color correction, although a lot of this depends on the host configuration—on a fast machine this setting won't have much of an impact. A Windows VM probably won't run Battlefield 4 or Middle-earth: Shadow of Mordor (we're lucky they're ported to Linux) when everything is cranked up to 11, but more older or less demanding games will work just fine: we spent a good hour playing the popular indie game Don't Starve, completely forgetting about our Comparison.

Everything worked better on VMware than on VirtualBox, but perhaps this was due to a more advantageous configuration - on Arch Linux we were using the latest proprietary Nvidia driver, which could lead to an advantage of one over the other.

Verdict

Virtualization is a long-standing and complex topic for comparisons. If you want to run 3D games, you won't even look at Gnome Boxes or Virt-Manager, and unless you get better results with VirtualBox than we do, you'll choose VMware as your hypervisor. But again, this technology is by no means as mature as DirectX 11 running in the native format. You may have even better luck with games in Wine [Ed.: - Or not.] with some experimental performance patches. We're generally not crazy about VMware licenses, especially ones that force you to pay after a 30-day trial, but for some, Workstation's enterprise-grade features will be a boon. Particularly if you use vCenter Converter from VMware, you virtualize a machine with one click - ideal if you want to test something new on your current system.

We haven't covered the ton of command line tools that come with all of our candidates, but they are there, along with more than copious documentation. You can use them in your scripts when you go all out on virtualization, pushing out a whole host of virtual machines from the safety of the command line environment. Perhaps hackers will prefer to work with Qemu directly, but those looking for a simple free and open source solution will be happy with Gnome Boxes.

The bubbles look good if you don't see the effort that went into rendering them.

But there is only one winner (a tie is a rare exception), and this time it is Virt-Manager - well, we couldn’t let VMware win. Virt-Manager allows you to harness most of the power of Qemu without resorting to lengthy command-line spells. Virtual machines can be paused, reconfigured, moved and cloned - all without much hassle. The only thing it lacks is support for graphics acceleration, but who knows, maybe it will appear. VMware Player and Gnome Boxes are tied for second place as they both score highly for their simplicity, and we love the Boxes icon, which features a tesseract (or a hypercube, or a cube within a cube - whatever you prefer).

Virt-Manager ★★★★
All managers should do such a good job.

VirtualBox ★★
Once the only solution, now on the sidelines.

VMware Player ★★★
Fast and convenient, but the license let me down.

VMware Workstation ★★
Fast and full-featured, but not free.

Boxes ★★★
The simplest way to install and configure a VM.

Today there is a small selection of visualization platforms; in general, it is limited to two options - VMware Workstation And Oracle VirtualBox. As for alternative solutions, they are either significantly inferior in functionality, or their release has been discontinued.

VMware Workstation– a closed-source platform, distributed on a paid basis. Only its incomplete version is open source - VMware Player. At the same time, its analogue – VirtualBox – is open source software (in particular, the OSE version is open source).

Friendly interface.
Ease of use of the network interaction editor.

VM disks that can grow in volume as data accumulates. Snapshots.

Work with a variety of guest operating systems, including the ability to run Windows and Linux as guests.

Work with 64 guest platforms.
Ability to play audio from a VM on host hardware
Both VM variants support multiprocessor configurations.

Ability to copy files between the host operating system and the VM Ability to access the VM console via an RDP server.

Moving the application from the virtual machine to the workspace of the main system - it seems that it works in the latter.

The ability to exchange data between the guest and host systems, while the data is stored in the clipboard, etc.

Supports 3D graphics for games and other applications Improved drivers in the guest OS, etc.

Benefits of VirtualBox

This platform is distributed free of charge, while VMware Workstation will cost more than $200.

Support for more operating systems - this VM runs on Windows, Linux, MacOs X and Solaris, while VMware Workstation only supports the first two from the list.

The presence in VB of a special “teleportation” technology, thanks to which a running VM can be moved to another host without first stopping its operation. The analogue does not have such an opportunity.

Supports a large number of disk image formats - in addition to the native .vdi, the platform works with .vdmk and .vhd. The analogue works only with one of them - .vdmk (the issue of working with images that have a different extension is solved using a separate converter that imports them).

More options when working from the command line - you can manage the virtual machine, snapshots, devices, etc. This VM has better audio support for Linux systems - while in VMware Workstation the sound is turned off on the host system, in VB it can be played while the machine is running.

CPU and I/O resource consumption can be limited; the competing VM does not provide this capability.

Adjustable video memory.

Benefits of VMware Workstation

Since this VM is distributed on a paid basis, the user is always provided with support.

More advanced support for 3D graphics, the level of stability of 3D acceleration is higher than that of its competitor VB.

The ability to create snapshots at certain intervals increases the reliability of working with the VM (similar to the autosave function in MS Word).

The volume of virtual disks can be compressed in order to free up free space for the operation of other systems.

More possibilities when working with a virtual network.
Linked clones feature for VMs.
Ability to record VM operation in video format.
Integration with development and testing environments, special features for programmers 256-bit encryption to protect VMs

VMware Workstation has a number of useful features. For example, you can pause the VM, shortcuts to programs are also created in the Start menu, etc.

For those who are faced with a choice between two virtual machines, we can give the following advice: if you do not have a clear idea of ​​what VMware Workstation is needed for, you can confidently choose the free VirtualBox.

Those who develop or test software are better off choosing VMware Workstation - it offers many convenient options that make everyday work easier that the competing platform does not have.

The concept of a virtual machine (from the English Virtual Machine) is understood as 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 operating operating systems and programs on it.

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

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

This technology came to the general public from the world of 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:

1. Optimizing the use of server resources.
2. Information protection, as well as limiting the capabilities of some programs, the so-called sandbox idea.
3. Research into new computer architecture or software.
4. Emulation of various computer architectures (for example, to emulate the PlayStation game console from Sony).
5. Creation of malicious code.
   For example, the SubVirt rootkit, created in 2006 by Microsoft Research (MSR), created a virtual work environment in which the user's operating system was placed 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 antivirus software, providing remote control over the virtual machine to the attacker.
6. Simulation of computer networks.
7. 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.

Supports audio devices and various types of network communication.

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 (slow system operation) 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 under open source (GPL license).

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

A feature of the PV mode is that there is no initial moment when the computer boots (imitation of BIOS code, boot loader) and the guest OS kernel starts immediately in the desired mode, like regular programs.

It is worth noting that Xen can be compared to enterprise-grade software 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

This program was originally 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 functionality from 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, so the full version of the program - VMware Workstation - is 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 of the free version.

Installing Windows 7 x64 on VirtualBox (virtual machine)

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

Virtualization allows you to encapsulate the internals of operating systems or parts of them 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 of machine virtualization:

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

Virtualization software, namely virtual machines for Windows 7 (Linux, Mac OS X), is typically a regular operating system application or service that allows you to create hosts. A host is any 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 virtualization methods that affect not only the implementation of applications for creating virtual machines, but also the capabilities provided to guest systems. There is conventional emulation, in which hardware and software calls pass through an 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), completely different hardware and operating systems may be required. 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 a 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 the real system in order for the virtual machine to function properly. 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 or directory sharing.

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 a more advanced networking stack, unlimited snapshots, some OpenGL and DirectX support, 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. There is also a portable version of 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, importing existing machines is difficult, disk management is not intuitive.

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 what you get is memory sharing for improved RAM efficiency, 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). Supports 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, very high performance under the right conditions.

Cons: UNIX-like systems only. 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 support for CD-ROM 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. A few command line utilities that can be confusing. Not easy to install and run. You must boot your own instance of the kernel.

Other solutions for creating virtual machines

There are many other solutions that were not listed here, such as Parallels Virtuozzo, OpenVZ and VMLite-based VirtualBox. There are also a number of redesigned solutions, including examples of crossing virtualization and thin clients. Linux also has a huge number of its own modifications. And don’t forget about cloud technologies with their virtualization applications.

However, if you are a novice user, then you should not chase possibilities and colorful modifications. Otherwise, trying to create a virtual machine to run a couple of programs can result in several sleepless nights.

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 the available hardware, requirements for ease of setup and startup, as well as the availability of the required set of 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.