▷ What is virtualization and what is it for

One of the great advances in computing has undoubtedly been virtualization. This gives us the possibility of having several operating systems within each other and thus save money and hardware resources.

Thanks to virtualization, companies have been able to considerably optimize their technological resources and the expenditure of money and, above all, physical space. In this article we are going to try to break down as much as possible about this technique and we are going to learn what advantages it offers us.

Index of contents

The possibility of having a Mac or Linux operating system inside a Windows was something we did not even imagine a few years ago. On the other hand, nowadays the strange thing is precisely the opposite especially when spoken of consulting companies or that offer web services through remote servers.

What is virtualization

We can say that the virtualization technique is about creating a virtual or non-physical version of an operating system or hardware platform thanks to software. So, when we virtualize, what we are really doing is taking the resources that a physical machine would have: CPU, RAM, Hard Drive, Motherboard, NETWORK, and everything that makes up a computer and simulating them using software that is installed in turn. within an operating system that operates on a physical machine.

This resource or tool that is capable of converting a physical computer into virtual lines of code is called Hypervisor or VMM (Virtual Machine Monitor). Thanks to this software we are able to abstract the physical resources of our computer and replicate them so that, in addition to being used by our real operating system, they can also be used by another operating system in an adapted way. This means that we have a 500 GB hard disk, we can tell this software to create from it a virtual 60 GB hard disk for another Windows. Or that 4 GB of our RAM memory go to this virtual Windows.

But this does not end here, not only can we install a second Windows and a third or more on our computer, but we can also have a server computer located elsewhere (remote server) and access the virtual operating systems that it has installed through the internet network. This is the true utility and power of virtualization.

Differences between physical and virtual operating system

For practical purposes, if we install a virtual operating system through software, we will obtain practically the same functionalities as in the physical operating system. The only downside is that this system will use the resources of the physical equipment, so its performance will be reduced.

When we boot a computer with a physical operating system, the hard disk provides a tool with which to boot this system, the MBR. In no case will the virtual operating system be able to start since this, despite being also located on the same machine, is encapsulated in a file that, in the eyes of our system, is a common and current data directory.

Types of virtualization

There are different types of virtualization, or rather different procedures to virtualize certain resources.

Server or hardware virtualization

This is the most common and most widely used method in the corporate server environment. The process is to create smaller virtual servers. The procedure is to create different small virtual servers or those that use few resources in a larger physical server and with powerful hardware. In this way, these machines, independent of each other, share the hardware resources to function efficiently.

In this method, the Hypervisor will control the processor, RAM, Hard Disk and the other components to allow different virtual operating systems to run simultaneously on the same machine. This has marked a before and after in companies dedicated to providing hosting servers and other types to other client companies.

• Savings in hardware: it will not be necessary to buy physical material for each equipment. we will only shell out money on a server. Scalability: to create new machines we will only have to increase the number of these and acquire new physical elements.

Software or operating system virtualization

This is the method that we desktop computer users will use in the vast majority of cases. The method is to allocate a main computer to create one or more virtual environments with operating systems installed on it.

Using a physical computer, we create a platform that allows, for example, a Linux operating system to be carried out within a Windows 10 operating system. The Linux system will have the characteristics of a real team, with its different devices taken directly from the available physical hardware resources.

Network virtualization

Through this method we can create physical networks in virtual networks to monitor a set of machines connected to each other. In this way we can recreate a physical network using software that will also be in charge of managing the intercommunication between the different connected resources.

• We will increase the data transfer rates: in the absence of physical limitations Savings in physical material: thanks to virtual connections we will not have the need to provide dedicated physical wiring to each of the machines. With the use of an interface of sufficient width such as fiber optics, we will have no problem transmitting all virtual data over a single physical connection. Scalability: As in previous technologies, this guarantees better scalability of resources.

Storage virtualization

Using this virtualization method, multiple storage resources are created, typically located and distributed over a network. By having several of these units and not just one, it will be possible to access them simultaneously or separately. In this way, access to data by multiple machines will be much more efficient and faster than if we had a single large hard drive available for multiple machines. In addition, the implementation of SSD flash drives allows this performance to be increased considerably. The advantages in summary are as follows:

Speed ​​increase: access to data will be faster when the units are divided.

• Better scalability: When we want to increase space, we will only have to buy new units leaving the ones we already have. Increased efficiency: there will be no waiting times since the available information is divided and access to it is direct and without waiting. Automatic resource management: the synchronization and management of these resources will be controlled by communication protocols, TCP / IP or those that use the different interfaces such as SAS or RAID.

Memory virtualization

The concept is exactly the same as for storage virtualization. The idea is to create a shared function memory through a distribution on the network for the different computers to use. It offers the same benefits as network storage.

Desktop virtualization

Using this virtualization method, we create a machine with an operating system in which other users can connect remotely and obtain the desktop of that server from another location. Advantage:

• Centralized location: it will only be necessary to have a computer with a single operating system, in which several users can connect remotely. Savings in software licenses Security: this way the files will be better protected than if they were on separate computers.

Virtualization software

As in all cases, we will have paid virtualization programs that are also free.

Payment programs:

• VMware: Owned by EMC Corporation is one of the most important and advanced tools on the market. Hyper-V: It is the Hypervisor owned by Microsoft and we will have it available for free if we acquire a license of Windows server or Windows 10 Pro Parallels: another of the most famous paid programs. It allows both software and hardware virtualization. Virtuozzo: Traditionally available on Linux, it came to Windows back in 2005.

Free programs:

• VirtualBox: It is the most famous open source software and also the one with the most utilities. Developed by Oracle, VirtualBox is available for Windows, Mac and Linux and is also capable of virtualizing all these Virtual PC operating systems: also owned by Microsoft and available for versions of Windows XP, Vista and 7 Xen: Developed by the University of Cambridge is open source software available for the Linux and Unix OpenVZ operating system: other open source software that is compatible only with Linux versions, both for hosts and virtual. KVM: another virtualization tool for the Linux operating system

Advantages of using virtualization

The advantages of using virtualization are many. Some of the most important are the following:

• Cost reduction: One of the most significant advantages is cost savings. Thanks to virtualization we will avoid buying hardware or licenses for more operating systems. Greater work efficiency: thanks to having the resources shared and scaled in different elements shared on the network, the efficiency of access to the data or resources is much faster. Lower energy consumption: this is directly related to the number of equipment connected to an electrical network. If we have virtual equipment, there will only be consumption of the platform that supports the other systems. Improved security: having physical equipment connected to a network increases the probability of data crashes. By server and storage virtualization this risk is greatly reduced. Less need for maintenance: a virtual machine has no physical components so they cannot fail. Cloning possibility: having a virtual machine, we can clone this as many times as we want or need to install anything extra. Portability: like the previous point, if we clone a machine, you can assign it to another server if you need to search for custom hardware.

Disadvantages of virtualization

White would never have existed if there were no black. As in all things, there are also some disadvantages in using virtualization method:

• Learning phase: one of the subjects to be overcome is precisely knowing how to use virtualization software. Personnel using this method must know exactly the possibility and use of virtualization tools, otherwise everything would end in disaster. Initial cost increase: to host several machines, it will be necessary to allocate resources to each of them. Therefore, it is necessary to invest in powerful software that perhaps a company does not have at first. Increase in chain failures: if the computer that serves as a virtual machine server fails, all of them will be inoperative, so a failure causes a considerable drop in performance.

In general, virtualization is an excellent tool very useful for companies and for users who have to test application and practice network configuration without the need for physical equipment.

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Have you wanted to create a virtual Windows ? We will see soon how to do it. We hope this article has helped you better understand what virtualization is.