Programs for the computer operating system are virtual machines. Virtual machines at home and in business

We got a little acquainted with processor virtualization technology and learned how to enable this function. Today we will continue the topic, we will install virtual operating systems on a computer, configure resources, and launch.

The issue features brief overview two of the most popular shells designed for creating and using virtual machines. These programs are also called hypervisors.

Virtual machines can be easily and independently installed on regular home computers, but they are also widely used on servers.

Virtual servers with virtual remote desktops are created to solve various problems on one physical computer.

What is a virtual machine on a PC and its purpose

It is quite suitable for personal use if you decide to learn a new operating system yourself. Now you don't have to have additional computer. No need to uninstall the usual Windows. You can study while looking at your email and social networks and at the same time gain skills in installing, configuring new, useful and interesting programs. This is how developers check the operation of applications in new and old environments, testing the operation of operating systems, programs and hardware.

But the main purpose is perhaps not this, but the obvious savings. It’s not for nothing that this technology has been developed for a long time. To operate servers, you first need high-performance equipment, which is expensive. A typical server uses its resources somewhere between 40-60%. And if there are two or more such servers, then it turns out that half of the capacity is idle.

To get rid of clustering, do not implement a bunch of physical servers and use virtual machines. On one computer you can install, for example, mail server, DNS server, domain controller and proxy server. With proper calculation and configuration, you will have four servers running on one physical server. The physical computer will operate at optimal power.

How to set up a Hyper-V virtual machine for Windows?

The hypervisor program is designed to install, configure, launch and manage virtual machines. In Windows 10, the developers made their own, built-in, so you don’t have to buy anything. By default, this snap-in is not visible in the operating system and we need to install it as an additional component. To do this, in the “Control Panel” we find the “Programs” link, and in it “Installation additional components Windows"

Check the boxes to mark the required components:

The installation of the hypervisor will begin and the changes will be applied. The system will ask to reboot.

When rebooting, do not forget to check whether processor virtualization is enabled in the BIOS!

What else do we need to launch a virtual operating system? All we have to do is find her iso image and download it to your computer. I have a Linux distribution called Fedora for astronomy enthusiasts in the form of an Iso. I wonder what operating system this is? Let's first find our Hypervisor. To do this, click on the “Start” menu, go down and find “Administrative Tools”.

You can display shortcuts on your desktop for convenience. The manager is designed to manage virtual machines. And “quick creation” speaks for itself. Click on this shortcut. By default, the system prompts you to create a Windows 10 virtual machine or Linux-Ubuntu. But today we will look for another image, click “Change installation source”:

Don't forget in " additional parameters» specify network adapter and the name of the virtual machine.

In Explorer we look for our desired operating system image:

Then press the big blue button:

Virtual machine Hyper-V created with default parameters, usually minimal system requirements to start. The system itself selects the number of processor cores and allocates the optimal amount RAM, creates a VIRTUAL hard drive based on the available space available. The location of the virtual machine is also automatically selected on the disk. But you can change all the settings for yourself. Before connecting, go to:

All parameters can be changed; We carefully read what is intended for what:

Then you can connect.

Like any operating system, a virtual one also requires installation. Everything is the same as in real life :)

Typical Linux installation:

After downloading graphical shell KDE, let's continue installing the distribution onto the VIRTUAL hard disk by selecting the appropriate shortcut:

The Hyper-V virtual machine is managed by clicking the buttons at the top of the panel:

Buttons allow you to start, pause, shut down, create a checkpoint, and also export the virtual machine. Everything is like in a real computer :). Hyper-V will be good on servers editions of Windows. True, you need to be able to configure a lot of things there. And this hypervisor crashed for me a couple of times after major cumulative updates of the “tens”. It had to be reinstalled.

Overview of the VM Workstation virtual machine, how to configure and install

Another popular solution is VM Ware Workstation. It's very flexible software solution, I had no problems with him. It's not free. But it's lightweight and works flawlessly, and was easy to set up. Download and configure the program. On the latest editions of Windows 10, the hypervisor will not start and the program will generate an error. If you get an error when starting the virtual machine for the first time vmware player and device/credential guard are not compatible, first .

We agree with the instructions of the master; After installation, reboot the computer. We find the startup file through the “Start” menu and click on it:

Open the program and create a new virtual machine.

Select the normal installation type:

Next, the wizard will prompt you to install the operating system as expected. He suggests doing this either from a CD/DVD disc or from an ISO file. I have the file on my disk, and that’s what I’ll use. In this example I'm installing Windows XP.

When using the "quick install" parameters such as computer name, keyboard layout, product key, user name, account, will be installed by default. This is not always convenient, and this data is corrected after installation, or at the time the operating system image is created. But in the latter case, you will have to go through all the stages manually - just like on a physical computer.

Don’t forget to specify the name of the virtual machine and its location in the next window.

Now we have reached the key settings. You must specify the size of the VIRTUAL hard drive:

Almost ready. For most operating systems, the hypervisor selects optimal sizes both memory and hard drive, but they can be changed later:

We launch the virtual machine, after which the installation of the operating system will begin. Please note that those connected to physical computer peripherals can also be used on a virtual machine. Some of them (flash drives, external hard drives) will need to be connected manually through the menu “Virtual machine” - “Connected equipment”

Managing virtual machines is clear and simple. There is also a control panel located at the top of the window:

Windows XP virtual machine on Windows 10, video

Let's see an example of creating a virtual machine in a short video:

Nothing complicated! Good luck!

Virtual machines, such as Virtualbox, are used to emulate virtual hardware and run multiple operating systems on a computer. The better your CPU and the more RAM you have, the faster the virtual machines on your computer will run.
I offer a few tips that will help you save time when initial setup virtual machines. This will be useful for working with VirtualBox, VMware, Parallels, or any other virtual machines.

Be sure to install the VirtualBox or VMware Tools guest OS add-ons

Installing the package is simple - in VirtualBox, after loading the guest operating system, click the Devices menu button and select “Install Guest Additions”. If you are using VMware, select "Install VMware Tools" from the Virtual Machine menu. Follow the on-screen instructions to complete the installation - if you are using Windows as a guest operating system, it will be the same as installing any other application.

Make sure you have the most latest version Guest Additions - If you see a notification that an update is available for Guest Additions or VMware Tools, you should install it.

Creating a fixed disk size during initial setup

For example, if you create a new virtual machine with a dynamically allocated disk with a maximum size of 30 GB, it will not take up to 30 GB of hard disk space immediately. After installing the operating system and programs, the disk may only take up to 10 GB. As files are added to virtual disk, it will expand to maximum size in 30 GB.

This can be convenient - each virtual machine will not take up an unreasonably large amount of space on your hard drive. However, it is slower than creating a fixed size disk (a disk with pre-allocated space). When creating a fixed size disk, all 30 GB will be immediately used on your computer.

There is a trade-off here - a fixed disk size takes up more space on the hard drive, but works with a virtual one hard drive faster. You will also get rid of file fragmentation - the space will be occupied by a large block instead of adding smaller chunks throughout the disk.

Exclude the virtual machine directory in your antivirus

To speed up the process, you can add your machine's virtual directory to the antivirus author's exclusion list. Once it is listed, your antivirus will ignore all files in that directory.

Allocate more memory

You can allocate more RAM in your virtual machine's settings dialog (the virtual machine must be shut down to do this). If your computer does not have enough memory to comfortably work with a virtual machine, you may notice a very large decrease in computer performance when using a page file on your hard drive.

Allocate more processors

If you are going to install an OS of the MS-Windows family and in the future, so that you can use more cores, specify 2 cores during installation so that the correct HAL is installed, after installation you can turn off the machine and install 1 core by default for everyday use. But for the future, you can always add kernels without uninstalling the OS. The Linux VM can dynamically detect any number of cores when the OS boots.

Adjust video settings

By and large, you need to minimize the use of 3D, for example Windows 7, by disabling Aero.

Make sure Intel VT-x or AMD-V features are enabled

To determine whether your Intel processor Intel VT extension, use utilities that show system information. If your processor supports this feature, but the option is not available in your virtual machine, you must enable this feature in your computer's BIOS. This option is usually enabled by default on motherboards with AMD processors.

Place the virtual machine files on another drive

However, you should not start the virtual machine with external drive(USB) - this will be much slower.

1. Dedicating additional processors is rarely a good idea. Use 1 CPU for desktop OS.
2. Try not to use graphical hypervisors for server operating systems.
3. Do not allocate more cores to running VMs than there are on your computer.

The concept of a “virtual machine” was born several decades ago, back in the late 60s of the last century. But then virtual machines were used not on personal computers, but on “large” computers such as IBM/370 (or their Soviet analogue - ES Computers), and their tasks were somewhat different: to provide each of the numerous users with their own, independent “piece” » resources of a computing monster.

Today, virtual machines are experiencing a rebirth. One of the "fathers" of the modern generation of virtual machines, Professor Rosenblum, attributes their revival to two main reasons:

■ the emergence of a large number of different operating systems (OS), which impose specific requirements on the parameters of the computer hardware components used;

■ high administration costs and complexity of servicing computers on which several different operating systems are installed (including in terms of ensuring the required reliability and security of operation).

A modern virtual machine allows you to hide some parameters from the operating system installed on it physical devices computer and thereby ensure the mutual independence of the OS and installed equipment.

This approach provides users (and/or administrators) computing systems) a number of advantages. These include in particular:

■ the ability to install several operating systems on one computer without the need for appropriate configuration of physical hard drives;

■ work with several operating systems simultaneously with the ability to dynamically switch between them without rebooting the system (Fig. 1.1);

■ reducing the time required to change the composition of installed operating systems;

■ isolation of real hardware from the unwanted influence of software running in a virtual machine environment;

■ possibility of modeling computer network on a single standalone computer.

Rice. 1.1. Multiple virtual machines on one desktop

Thanks to these advantages, the range of tasks that the user can solve without rebooting the system and without fear of causing any damage to it or completely disabling it is significantly expanded. Here are just some examples of such tasks:

■ mastering a new OS;

■ launching applications designed to work in a specific OS environment;

■ testing one application running different operating systems;

■ installation and removal of evaluation or demo versions of programs;

■ testing potentially dangerous applications, regarding which there is suspicion of viral infection;

■ managing user access rights to data and programs within a virtual machine.

The reader himself will probably easily add two or three situations to the above list when having a virtual machine on the computer would be very useful.

Which users would like to learn how to work with virtual machines? Perhaps everyone who has more than one OS installed on their computer. And also for those who want to master a new operating system, but do not dare to immediately abandon the previous one. Virtual machines are very useful for teachers of various computer courses and disciplines, as well as developers of multi-platform software products. They are of particular interest to web designers: after all, the pages they create should look equally attractive to users working on the most different systems and platforms. With the ability to quickly switch from one environment to another using a virtual machine system, the “right” web designer is unlikely to miss the chance to test the results of his work in different web browsers.

All of the listed advantages of virtual machines are common to many of them. Besides these general properties, a specific software product usually has individual characteristics designed to increase its attractiveness in comparison with competing products.

On the websites of virtual machine developers you can find numerous examples of the use of virtual machine technology by various well-known companies. Thus, VMware virtual machines are used by Symantec to test network antivirus packages; programmers popular search engine Google uses VMware virtual machines to measure performance Google work with different web browsers and on different platforms.

Let's start by clarifying the terms.

From the user's point of view, virtual machine (VM) - This is a specific instance of a certain virtual computing environment (“virtual computer”), created using a special software tool. Typically, such tools allow you to create and run an arbitrary number of virtual machines, limited only by the physical resources of a real computer.

The actual tool for creating VMs (sometimes called virtual machine application, or FDA) - This normal application, installed, like any other, on a specific real operating system. This real OS is called the "host" or host, OS (from the English term host - “main”, “base”, “master”).

All tasks for managing virtual machines are solved by a special module as part of the VM application - Virtual Machine Monitor (VMM). The monitor plays the role of an intermediary in all interactions between virtual machines and basic equipment, supporting the execution of all created VMs on a single hardware platform and ensuring their reliable isolation. The user does not have direct access to the VMM. In most software products, it is provided only with a graphical interface for creating and configuring virtual machines (Fig. 1.2). This interface is usually called virtual machine console.

Rice. 1.2. Example of a virtual machine console

“Inside” the virtual machine, the user installs the operating system he needs, just like on a real computer. Such an OS belonging to a specific VM is called guest(guest OS). The list of supported guest operating systems is one of the most important characteristics virtual machine. The most powerful modern virtual machines (presented in this book) provide support for about a dozen popular versions of operating systems from the Windows, Linux and MacOS families.

When the virtual machine is created and running, the user may have the complete illusion that he is working with standalone computer, which has its own processor, RAM, video system and (usually) a “standard” set of external devices, including a floppy drive and a CD/DVD reader.

In fact, the virtual machine does not have access to the physical resources of the real computer. Work with them is assigned to the previously mentioned MVM, as well as to another utility program- virtual machine driver.

In a simplified form, the architecture of the system that uses virtual machines is as follows (Fig. 1.3):

■ the host OS and the virtual machine monitor share rights to manage the computer’s hardware components; at the same time, the host OS distributes resources between its own applications (including the VM console);

■ the VM monitor controls the distribution of resources between running virtual machines, creating for them the illusion of direct access to the hardware level (this mechanism is called virtualization);

■ guest operating systems, within the resources allocated to them, manage the operation of “their” applications.

Rice. 1.3. Virtual machine system architecture

The architecture shown is very general. However, the virtual machine systems on the market today have significant differences. They are determined primarily by the virtualization mechanism used in a particular system.

A virtual machine system can be built on various platforms and using different technologies. The virtualization scheme used depends both on the hardware platform and on the characteristics of the “relationship” between the host OS and the supported guest OS. Some architectures provide virtualization capabilities at the hardware level, while others require additional software tricks.

Currently, three virtualization schemes are widespread:

■ guest OS API emulation;

■ full emulation of the guest OS;

■ quasi-emulation of the guest OS.

Typically, applications operate in an isolated address space and interact with hardware using the Application Programming Interface (API) provided by the operating system. If two operating systems are compatible in their API interfaces(for example, Windows 98 and Windows ME), then applications developed for one of them will work on the other. If two operating systems are incompatible in their API interfaces (for example, Windows 2000 and Linux), then it is necessary to intercept application calls to the guest OS API and imitate its behavior using the host OS. With this approach, you can install one operating system and work simultaneously with both its applications and applications of another operating system.

Since all application code runs without emulation, and only API calls are emulated, this virtualization scheme results in a negligible loss in virtual machine performance. However, due to the fact that many applications use undocumented API functions or access the operating system bypassing the API, even very good emulators APIs have compatibility issues and allow you to run no more than 70% of the total number of applications. In addition, maintaining API emulation of a rapidly evolving operating system (such as Windows) is very difficult, and most API emulators remain emulators of a specific version of the operating system. Thus, Windows NT/2000 still has a built-in emulator for OS/2 version 1.x applications. But the biggest drawback of a VM with guest OS API emulation is its focus on a specific operating system.

Examples of products made using guest OS API emulation technology:

■ project with open source Wine (Wine Is Not an Emulator, “Wine is not an emulator”), which allows you to run DOS, Win16 and Win32 applications under operating system control Linux systems and Unix;

■ Netraverse's Win4Lin product, which allows you to run Windows operating systems running the Linux operating system;

■ DOSEMU open source project, which allows you to run DOS applications running the Linux operating system;

■ the open source project User Mode Linux (UML), which allows you to run multiple copies of the Linux operating system on a single computer (currently built-in and Linux kernel version 2.6);

■ Virtuozzo technology, developed by the Russian company SWsoft, which allows you to run multiple copies of the Linux operating system on one computer.

Projects that support full emulation technology work on the principle of interpreting instructions from the guest OS command system. Since this completely emulates the behavior of both the processor and all external devices, it is possible to emulate a computer with Intel architecture x86 on computers with completely different architectures, such as Mac workstations or Sun servers with RISC processors. The main disadvantage of full emulation is the significant loss of performance of the guest operating system (the speed of “guest” applications can drop by 100-1000 times). Therefore, until recently, VMs with full emulation were most often used as low-level debuggers for examining and tracing operating systems. However, thanks to significant growth computing power Even “desktop” computer VMs with full emulation have become quite competitive today. The most prominent representative of this type of VM is the Virtual PC product from Connectix (now acquired by Microsoft), which is described in detail in Chapter 2 of the book. Other examples of projects implemented using full emulation technology include the following:

■ Bochs open source project, which allows you to run various operating systems Intel systems x86 for Linux, Windows, BeOS and Mac OS;

■ Simics product from Virtutech, which allows you to run and debug various Intel x86 operating systems running Windows and other operating systems;

■ Qemu project - an emulator of various architectures on PC,

Guest OS quasi-emulation technology is based on the fact that not all guest OS instructions need to be emulated using the host operating system. Many of the instructions needed to correct operation"guest" applications can be directly addressed to the host OS. The exception is instructions for controlling devices such as a video card, IDE controller, timer, and some others.

Thus, during RM operation with quasi-emulation, selective emulation of guest OS instructions occurs. Obviously, the performance of such a VM should be higher than that of a VM with full emulation. However, as stated, at the performance levels achieved personal computers the difference turns out to be not so noticeable.

Examples of projects made using quasi-emulation technology:

■ Virtual Platform technology, on the basis of which VMware offers four products: VMware Workstation for Windows NT/2000/XP, VMware Workstation for Linux, VMware GSX Server (group server) and VMware LSX Server (enterprise server);

■ virtual machine Serenity Virtual Station (SVISTA) (formerly twoOStwo), developed by the Russian company Parallels for the German company NetSys GmbH;

■ the open source project Plex86, which allows you to run various Intel x86 operating systems under Linux control.

■ open source project L4Ka, which uses a microkernel;

■ open source project Xen, which allows you to run modified Linux, FreeBSD, NetBSD and Windows XP operating systems running Linux, FreeBSD, NetBSD and, subject to certain conditions, even providing a performance increase.

The subsequent chapters of the book examine the most popular representatives of various types of virtual machines today: Virtual PC 2004 from Microsoft, VMware Workstation from VMware and a relatively “fresh” product - Parallels Workstation, created by Parallels. Moreover, the description of all competing programs is built according to the same scheme, so that it is easier for the reader to compare them with each other and make an informed choice.

Notes:

Mendel Rosenblum(mendel@ cs.stanford.edu) is a professor of computer science at Stanford University and one of the founders and chief scientist of VMware. Chapter 3 of the book is devoted to working with this company’s virtual machine, VMware Workstation.

Currently, Parallels has split into two independent companies. The first of them, which retained the same name, promotes its product under the Parallels brand; the second, called Serenity Systems International (http://www.serenityvirtual.com), on the contrary, uses the previous name of the product - SVISTA - and its logo; both versions of virtual machines can run on Windows NT/2000/XP and Linux.

Every PC user sometimes wants to try some other operating system, but does not dare install it on his work computer. Indeed, installing an unfamiliar OS is a very risky action. With one wrong command you can lose all the data on the disk. But today there is a way to try several operating systems on one computer at once, and, if desired, even simultaneously! This method is called - virtual machine or virtual computer. Let's look at the three best programs that allow you to use virtualization technology at home.

General information about virtual machines

Virtualization systems existing today have much in common. In particular, each virtual machine recognizes a CD drive as well as a floppy drive. In addition, it is possible to work with virtual drives and disk images. Very useful is the ability to manually set the amount of RAM for each virtual machine, the list of connected devices, etc. Such flexible settings allow you to comfortably use the guest system. Very convenient function is the ability to pause the virtual machine at any time. This frees up necessary hardware resources for the host system.

All the differences between existing virtual machines, in fact, come down only to the list of supported ones operating systems, as well as cost. Most common today VirtualBox systems, Windows Virtual PC and VMWare. How are they different?

ORACLE VirtualBox - a universal, free virtual machine

VirtualBox- very simple, powerful and free tool for virtualization, developed thanks to the support of the famous ORACLE corporation. Allows you to install almost any modern operating system as a “guest”, be it Windows, MacOS or any of the many representatives of the Linux family.

Creating virtual machines in VirtualBox is done using a step-by-step wizard. Any more or less experienced PC user can understand how it works. The system supports working with networks, therefore, if desired, you can give the virtual machine access to the Internet.

VirtualBox allows you to create "snapshots" of the operating system. With their help, you can create “restore points” to which you can “roll back” the guest system at any time in case of errors or failures.

Windows Virtual PC - virtual machine from Microsoft

Windows Virtual PC- a virtual machine for working only and exclusively with Windows. Installing Linux, MacOS and other operating systems are not supported.

Virtual PC allows you to run several different copies of Windows on one computer. In this case, you can set their priority so that automatic mode allocate to the needs of a particular virtual machine more resources, slowing down the work of others.

Monoplatform virtual Virtual machines PC is its main drawback. However, if you only need to test programs running on Windows, this is not relevant. One of the disadvantages is that the interface is less functional and less convenient than in VirtualBox. Otherwise, Virtual PC is a completely reliable tool that allows you to create virtual machines with operating systems. Microsoft systems Windows.

VMware Workstation - for serious tasks

VMware Workstation is a powerful, paid, highly reliable virtualization program that supports Windows and Linux. This machine is not intended for virtualization of MacOS.

Due to its high reliability and wide functionality, VMware Workstation is often used not only for testing, but also for the constant operation of virtual machines as servers, be it a firewall separating an organization’s network from the Internet or even a database server.

VMware Workstation is highly customizable, including many hardware options and options network connections for working with the Internet. This system is better than others in playing graphical applications on virtual machines, since it has a special virtual 3D accelerator for obtaining high-quality graphics.

The VMware Workstation interface is quite well organized, so getting used to all its rich functionality is quite easy. The program fully supports the Russian language.

It should be noted that VMware Workstation has a free “little brother” - VMWare Player. The player cannot create virtual machines, but allows you to run those previously created in VMware Workstation. This program will be useful in testing cases when, for example, a developer automated system They will submit it for review in the form of a virtual machine image. This practice is becoming increasingly widespread because it saves the user from having to deploy an unfamiliar program themselves.

IN lately You can often see articles on the Internet devoted to virtual machines. Mostly there is information on the Internet about various types similar machines, links to download them and similar information. The average user often cannot understand what they are and what they are needed for.

Virtual machines are special computer programs, which run directly from the operating system. These programs are a kind of emulators for the computer. They have:

• Hard drive (namely, a specially designated space on the computer’s hard drive);
• BIOS;
• CD-ROM (either the user's computer or a connected ISO sample);
• Network adapters (to provide connection to a computer, network resources and other virtual machines).

Just like on a real computer, an operating system can be installed on a virtual machine (and it doesn’t matter which one). Thus, the user will have the opportunity to test various operating systems without leaving his own (permanent) one.

The user will be able to exchange files between the guest and host operating systems without any problems. Implemented this action by simply dragging and dropping files from file manager client to the guest system window (or vice versa). Using a virtual machine is very convenient for testing automatic installation. For this bootable iso image is connected instead of a CD-ROM (this is done in the virtual machine settings), after which the installation of the system begins (just like on a regular computer).

In an office or corporate network, virtual machines are used, for example, to build virtual server. Such a server will be used exclusively by one organization for certain purposes (for example, for exchanging files between employees, storing valuable information). IN in this case It's best to use two virtual machines to ensure maximum safety server.

Virtual machines have been around for a long time network administrators to conduct experiments with software, which may be obtained from an unreliable source and therefore be potentially dangerous. Such programs run on a virtual machine, rather than on a real machine, and are scanned accordingly to detect harmful viruses. Using virtual machines, you can create separate nodes that will detect and “catch” all kinds of viruses aimed at destroying the main nodes local network. Also, virtual machines can transfer “caught” viruses to the servers of specialized companies that neutralize them and develop programs to prevent them.