What are Virtual Machines?
A virtual machine is a computer file, typically called an image, which behaves like a real computer. In other words, create a computer in a computer. It works in a window, just like any other program, giving the end-user the same experience on a virtual machine that it would have on the host operating system itself. The virtual machine is on the sandbox from the rest of the system, which means that the software inside a virtual machine can not escape the computer itself. This produces an ideal environment for testing other operating systems, including beta versions, access to data infected with the virus, creating operating system backups, and running software or applications on operating systems for which they have not been originally intended.
Several virtual machines can work simultaneously on the same physical computer. For servers, multiple operating systems work side by side with a software called a hypervisor to manage them, while desktop computers typically use an operating system to perform other operating systems in its program windows. Each virtual machine provides its virtual hardware, including CPUs, memory, hard drives, network interfaces, and other devices. The virtual hardware is then mapped to the actual hardware on the physical machine that reduces costs by reducing the need for physical hardware systems as well as the associated maintenance costs that accompany it and reduce the demand for power and cooling.
What are Virtual Machines used for?
Virtual machines (VMS) allow a company to run an operating system that behaves like a completely separated computer in an application window on a desktop. Virtual computers can be deployed to accommodate different levels of power requirement processing, to perform software requiring a different operating system, or to test applications in a safe and sandy environment.
Virtual machines have always been used for server virtualization, which allows IT, teams, to consolidate their IT resources and improve efficiency. Besides, virtual machines can perform specific tasks considered too risky to perform in a host environment, such as access to the operating systems of data infected with the virus or tests. Since the virtual machine is separated from the rest of the system, the software inside the virtual machine can not alter the host computer.
Types of Virtual Machines
System Virtual Machine
A “virtual machine” was originally defined by Popek and Goldberg as “an effective duplicate isolated from a real computer machine”. Current use includes virtual machines that have no direct correspondence to the real material. The physical material “from the real world” running the virtual machine is usually called “host” and the virtual machine emulated on this machine is usually called “guest”. A host can imitate several guests, each one that can imitate different operating systems and material platforms.
The desire to execute multiple operating systems was the initial motivation for virtual machines, to allow time-sharing between several operating systems to a single task. In some respects, a system virtual machine can be considered as a generalization of the concept of virtual memory that preceded it historically. CP / CMS of IBM, the first system for the virtue of complete virtualization, the implementation of time-sharing by providing each user with a single-user operating system, the conversational monitoring system (CMS). Unlike virtual memory, a system virtual machine entitled the User to write preferred instructions in their code. This approach has some advantages, such as the addition of unauthorized input/output devices by the standard system.
While technology evolves virtual memory for virtualization, new memory supercharging systems can be applied to handle memory sharing between multiple virtual machines on a computer operating system. It may be possible to share memory pages containing identical materials among several virtual machines that run on the same physical machine, which can lead to the mapping of the same physical page by a technique called core the merger of the same page (KSM). This is particularly useful for read-only pages, such as detention code segments, which is the case for multiple virtual machines running the same software, software libraries, web servers, middleware components, etc. Guest operating systems do not need to comply with host hardware, allowing them to perform different operating systems on the same computer (for example, Windows, Linux, or earlier versions of an operating system ) to support future software.
The use of virtual machines to support separate operating systems is popular concerning embedded systems. A typical use would be to execute a real-time operating system simultaneously with a preferred complex operating system, such as Linux or Windows. Another use would be for new and unproven software in the development phase so that it is in a sandbox. Virtual machines have other benefits for the development of the operating system and may include improved debugging and faster restarts.
Several VMS performing their guest operating system are frequently committed to server consolidation.
Process Virtual Machine
A process Virtual Machine sometimes called the application virtual machine, or Managed Runtime Environment (MRE), works as a normal application in a host operating system and supports a unique process. It is created when this process is started and destroyed when it exits. Its objective is to provide an independent programming environment for the platform that will solve the details of the underlying hardware or operating system and allows a program to perform in the same way on any platform.
A VM process provides high-level abstraction – that of a high-level programming language (concerning the low-level ISA abstraction of the VM system). Process VMS are implemented using an interpreter; performance comparable to compiled programming languages can be obtained through the use of a compilation just in time.
This type of VM has become popular with the Java programming language, which is implemented using the Java virtual machine. The other examples include the Parrot Virtual Machine and the .NET Framework, which operates on a virtual machine called the current language of execution. All can serve as a layer of abstraction for any computer language.
A special case of process VMS are systems that summarize the communication mechanisms of a computer group (potentially heterogeneous). Such a VM does not consist of a single process, but a physical machine process in the cluster. They are designed to facilitate the programming of simultaneous applications by leaving the programmer focused on algorithms rather than communication mechanisms provided by interconnection and operating systems. They do not hide the fact that communication takes place and, as such, do not try to present the cluster as a single machine.
Unlike another process VMS, these systems do not provide specific programming language, but are integrated into an existing language; Typically, such a system provides links for multiple languages (E.g., C and Fortran). Examples are the Parallel Virtual Machine (PVM) and a Message Passing Interface (MPI). These are not strictly virtual machines because applications running on top always have access to all operating system services and are therefore not limited to the system model.
Best Free Virtual Machine Software for Windows and Mac
1. VirtualBox (Mac and Windows)
If you are new to virtualization, your best choice to use a virtual machine for the first time in VirtualBox of Oracle. This hypervisor is open and free, and you can use it at work as simple as installing it on your computer at home.
VirtualBox was published in 2007 and quickly won popularity in the computer industry for its long list of supported operating systems. You can run any version of Windows from XP from it, OpenBSD, Solaris, and OpenSolaris set. Besides, you can easily install any version of Linux 2.4 and more.
This virtual machine is ideal for developers with Hardcore-Nostalgia windows. VirtualBox allows you to install NT and Server 2003 versions as well as older versions such as Windows 3.x or even IBM OS / 2 on the 2018 computers of the last generation.
Apple users have the same pleasure to use VirtualBox on their machines and the ability to host a Mac VM client session is a plus for any developer there. Given that Apple only allows their systems to work on their branded hardware, you will not be able to run macOS Mojave on a virtual machine using VirtualBox, unless you have a Mac.
One of the best aspects of the use of VirtualBox is its portability which allows you to transfer a virtual machine from one host to another, regardless of the operating systems. Besides, this hypervisor allows you to run multiple host windows at the same time on the same machine.
Another excellent feature of VirtualBox is the transparent mode, allowing you to run Windows applications and macOS side by side. The hypervisor optimizes system resources and hardware performance to reward you with the experience of the guest performance transparently in the host. This process is available under the GPL 2 (if you are using VirtualBox OSE) and for free.
VirtualBox should be your Virtual Machine Go-to a virtual machine if you use older hardware. It provides you with a reliable resource of available guest additions for free and allows you to transfer files and data between the host and the guest, regardless of the operating systems. More than that, this open-source hypervisor supports USB devices, 3D virtualization, and video.
VirtualBox New users can find an excellent source of information and tutorials on the Oracle website, as well as a long chain of pre-constructed virtual machines. Tutorials and guides of how guides are also available if you are blocked at any time during the installation process.
So far, VirtualBox has collected more than 100,000 registered users who form a busy and enthusiastic community that you can also join to access the latest software releases. Here are the main features of VirtualBox in a word:
- Open source and free.
- Works with Windows, macOS, Solaris, and Ubuntu.
- Allows seamless mode.
- VirtualBox drag and drop.
- Multi-Screen resolutions.
2. VMware Workstation Player (Windows and Linux)
VMware is one of the leading developers of virtual machines. Their brand hypervisors include VMware Fusion (macOS) and VMware Workstation (PC). Both applications have the same characteristics and ease of use, but each of their configurations is carved on the respective operating systems.
VMware Workstation Player for Windows or Linux is free if you use it for personal purposes. However, if you want to upgrade to the PRO version, you will have to pay for the license key, which can give your budget at least $ 100.
VMware Workstation has one of the largest databases of computer industry followers, mainly due to high standards of virtual machine software that the company has respected since its market launch more than 20 years ago. Users are delighted with the ability to run advanced 3D solutions on a hypervisor that supports both DirectX 10 and OpenGL 3.3 and maintain video and photographic quality throughout the process.
An interesting feature of VMware WorkStation Player is the snapshot system that allows you to create multiple instances of the virtual machine and set multiple restore points during a test process. In this way, if something is wrong, you can go back to a previous version or clone, also called isolated liners to resume your progress.
If you choose the workstation player as a virtual machine, you can accommodate more than 200 clients and share files and data between them and the host at a transparent rate. Besides, you can connect to VSphere, which is the VMware cloud storage system and that can be used as a remote data center for your hypervisor.
The VMware Workstation player is a reliable virtual machine, but it falls short when you compare it to its pro pay version. Even if both can support 4K displays with ease, the free app works more slowly with each host you add to the virtual machine, starting with the second. Besides, it makes the cloning and snapshot system almost impossible to use at a decent speed. If you want to use this software for business purposes, your best choice would be to use a professional license.
- Works on Windows and Ubuntu.
- Supports DirectX 10 and OpenGL 3.3.
- Unity Mode.
- Incorporates a snapshot feature.
- Supports 4K displays.
3. VMware Fusion (Mac)
We will help you find a virtual machine solution that has more support for RAM and CPU allocation for your guest operating system that will not abandon an excessive amount of RAM or CPU in your Mac or Your host computer. It must also be able to share sampling files by dragging them and dropping them on your virtual machine. It should also have high-resolution capacities with a 4 / 5k Retina display bracket. Finally, it must be able to execute Bootcamp in your virtual machine. You should be able to run it through Windows on your macOS.
VMware Fusion in Macos Mojave
If this high-performance solution style sounds like the best fit for you, the best solution will be “VMware Fusion”. If you are a developer, you will also like a feature that you will love on VMware Fusion that helps you connect to what is called “vsphere / ESXi server”, which is also called 3D graphic rendering installation that is perfect for IOS developers.
VMware Fusion Settings
- VMware Fusion allows you to create extended virtual machines with up to 16 processors and 64GB of RAM usage that will suit you perfectly if you have a powerful Mac such as a MacBook Pro.
- Mode of view of the unit; As a seamless mode, this allows you to use the coast of the multiple operating systems next to your virtual machines such as Windows and Mac. There is also a drag-and-drop file sharing installation between the two operating systems.
- There is a guest tool that allows you to enable 3D graphics within your VMware Fusion virtual machine with direct x 10.1 and OpenGL 3.3 direct players, players and developers will love this feature.
- Support for high resolution 4K / 5K retina support.
- An SSH click for Linux; If you run a Linux virtual machine that has the enabled SSH service, you can quickly and easily configure your SSH connection so that you can connect to the virtual machine.
- Virtual network simulation; This advanced feature allows you to use virtual network adapter settings to control the bandwidth limits on your virtual machine and specify the percentage of accepted packet loss, as well as the creation of network latency for transfers. Incoming and outgoing data in your virtual machine.
- VMware Fusion could be a powerful virtual machine solution; However, you need more knowledge and have a more steep learning curve than alternative solutions.
4. Parallel’s Software (Mac)
If you are new virtual machines, Parallels Desktop is probably the best choice for you. It is first because it helps you locate the ISO Installer file and will help you download it on your desktop. It can also help you find an Android, Ubuntu, or Windows image depending on the software you want to run, and finally, it will help you create an installation from the macOS recovery disk.
Windows 10 in the parallel office
This software that we have mentioned already helps you run Windows, Android, or Linux operating systems on your Mac without having to restart the machine. It also allows you to install a virtual machine to execute Mac OS from disk recovery if you wish.
Virtual RAM and CPU in a parallel office
However, like all these solutions, each of them has advantages and disadvantages. They are:
- It is effortless to use and perfect for Newbie. It has a one-click installation, then you can connect to your parallel office on the Internet. As we also mentioned, it helps you find and download the installation file. This means that if you have very little knowledge about virtual machines, you can always use them.
- Another useful feature is called “one-click tuning” which allows you to meet your experience based on productivity, games, designs, software tests, or even the application. The software itself will provide performance according to your intentions and goals.
- The standard edition supports up to 8 GB used of VRAM and four VCPU. If you are an average user of virtual machines, this should be more than enough resources to execute macos.
- The coherence mode allows you to run Windows next to Mac OS. You can also share files and folders using a simple drag and drop feature between these two operating systems.
- The guest tool as we mentioned allows 3D charts of your virtual machine, making the experience more optimal and seamless.
- Finally, it works with the training camp that will allow you to execute macos.
- Removing a virtual machine via the parallel desktop is difficult for Newbie because there are many modifications and delete buttons, but many of them do not close the virtual machine.
- If you need more resources such as RAM and CPU, you will need to upgrade to the pro version to have these features.
5. Hyper-V (Windows)
Hyper-V is a domestic virtual machine for Windows. The company has published this hypervisor for Windows Server in 2008 and is slowly but gradually becoming one of the preferred software applications of the developers and professionals here.
Hyper-V is ideal for new developers mainly because of its ease of use and implementation. A good way to put it is that with the help of these virtual machine input level programmers, can reach a high level of productivity and performance in a short time.
Hyper-V is perfectly integrated with Windows 10 and compatible with a large number of servers. The software can be installed in a Windows server or as a stand-alone unit, also called Hyper-V server.
One of the biggest advantages of Hyper-V uses when your main virtual machine is the ability to snap your virtualization process and clone multiple versions of the virtual machine in a secure and isolated environment for future use.
Another impressive feature of this hypervisor is the virtual switch. Hyper-V uses this tool to give you extensive connectivity and allows you to connect your virtual machines to virtual networks and physical networks alternately.
The Hyper-V virtual switch allows you to view the virtualization process statistics between machines and display an overall image of the administrators. It also uses resource monitoring, balances network availability, and bandwidth use, and the number of virtual machines to ensure good resource distribution and reliable performance.
Overall, Hyper-V should be a reliable choice for Windows users. Here are the main features of this hypervisor in a word:
- Native to Windows
- Flexible and easy to use
- Easy backups
- Uses the Virtual Switch
6. Gnome Boxes
Gnome boxes are a creative and management tool for virtualization designed for Linux and can help you customize all kinds of virtualization tools – from specific workstation configurations to enable operating systems. The simple and elegant interface makes it easy to see which virtualization systems you have at any time and how they occur. If you are looking for a friendly virtualization solution for Linux, give gnome boxes a shot: it plays exceptionally well with Qemu and Vir Manager, which are ideal tools for more back-end jobs.
Note that the boxes will automatically allocate resources for virtualization based on the supplier’s recommendations. If the boxes can not find recommendations or processor virtualization information, it will automatically assign 20 GB storage and 500 MB of RAM, so be prepared for that.
7. Boot Camp
We know that you may be intrigued by Apple’s workout camp, so even if it is not technically a virtual machine, we will enlighten you on its mechanism. The software, included on all Macs, allows users to double start MacOS and Windows. Instead of emulating an operating system, Boot Camp helps you configure a partition on the hard disk to install the Windows operating system of your choice. As it works directly on the hard drive, the running windows via Boot Camp lead to a much better experience than any offer of virtual machines.
The disadvantage of Apple’s training camp is that it uses a partitioning of the disk; That is, it separates your disk space so as not to be able to perform Windows applications simultaneously and the best Mac applications. Besides, if you want to pass Mac applications to Windows Apps or vice versa, you will need to restart your computer.
It should be noted that while boot camp itself is not a virtual machine, you can run your drive camp partition as a virtual machine with parallels 14 (described above). This utility gives you quick access to Windows when you want in the MacOS and complete performance when you have enough time to restart your computer and start Windows directly.
In all virtualization, the virtual machine simulates enough hardware to allow an unmodified “guest” operating system (the one designed for the same set of instructions) to execute in isolation. This approach was pioneered in 1966 with IBM CP-40 and CP-67, predecessors of the VM family.
Examples located outside the mainframe field include Parallels Workstation, Parallels Desktop for Mac, VirtualBox, Virtual Iron, Oracle VM, Virtual PC, Virtual Server, Hyper-V, VMware Workstation, VMware Server (Intercontinure, formerly GSX Server), VMware Esxi, Qemu, Adeos, Mac-on-Linux, Win4BSD, Win4lin Pro and Egenera Vblade Technology.
In hardware-assisted virtualization, the hardware provides architectural support that facilitates the construction of a virtual machine monitor and allows you to execute invited operating systems. The hardware-assisted virtualization was introduced to the IBM / 370 system in 1972, intended for use with VM / 370, the first operating system of the virtual machine offered by IBM as an official product.
In 2005 and 2006, Intel and AMD provided additional material to support virtualization. Sun Microsystems (now Oracle Corporation) added similar features in their UltraSparc Series processors in 2005. Examples of virtualization platforms suitable for such equipment include KVM, Workstation VMware, VMware Fusion, Hyper-V, Windows Virtual PC, Xen, Parallels Desktop for Mac, Oracle VM Server for SPARC, VirtualBox and Parallels Workstation.
In 2006, the first-generation 32 and 64-bit X86 material support was found to be rarely offering performance benefits on software virtualization.
The best free virtual machine software in 2021 gives you a good idea of virtualization and its significant importance for professionals and computer developers. This type of application increases in popularity with each month that passes because they offer more and more solutions for users who need to get multiple operating systems running on the same machine.
Depending on your equipment (PC or Mac), you can choose between several reliable free virtual machine applications that will work properly and efficiently. Most hypervestisers on the market, especially those addressed in this article have a short learning curve, which makes them ideal for new users. If you are looking for a way to expand your knowledge and use of multiple operating systems, virtualization is the thing for you.