Technology of vps virtualization is an effective approach to the optimal use of server hardware resources, providing the division and distribution of them among multiple virtual machines. Relying on virtualization you can effectively "split" a single physical server into several virtual instances with a unique set of software and operating systems. Moreover, each is surrounded by virtual walls, completely isolated and independent of the others.
The advantages of virtualization are obvious: each user can see and use only his own virtual environment, which gives the impression of working on a separate dedicated server. It reduces hosting maintenance and support costs: a single physical machine is sufficient for the efficient operation of several virtual servers.
Software virtualization
In software virtualization, server resources are shared through operating system (OS) operations, with virtual machines operating on a common software kernel.
The advantage is speed and ease of configuration. The creation of virtual machines is fast, which contributes to the rapid operation of the system. The disadvantage of this approach is the limited full resource sharing. The load on one virtual machine can affect the performance of other virtual machines on the same server.
That is, a single server kernel is used by all virtual machines, working with amazing speed and performance. OS reinstallation takes seconds. But often providers practice excessive overselling (reselling resources) by running too many virtual servers. This can lead to resource scarcity and slow system performance. Usually, providers use moderate overselling, which is almost invisible to users.
OpenVZ
This is software virtualization using the Linux platform. It is widely used among hosting providers. However, VPS/VDS servers on OpenVZ can be inconvenient due to uneven distribution of resources between containers (virtual environments).
Virtuozzo is a commercial platform for software virtualization based on the Linux system, a reliable analog of OpenVZ developed by Parallels.
All new virtualization features and innovations first appear in the paid version of Virtuozzo and are then transferred to OpenVZ. In this way, hosting providers can access advanced features and technologies, providing better services.
All the shortcomings of the free version of OpenVZ mentioned above have been eliminated in Virtuozzo, which ensures stable and reliable operation of virtual servers.
Hardware virtualization
A standard operating system is installed and fully isolated virtual machines are created. Each runs on its own operating system and uses its own kernel.
An important advantage of hardware virtualization is the complete sharing of server resources - the operation of one virtual machine (VM) does not adversely affect the performance of others and does not limit the allocation of resources for them.
Hardware virtualization is slightly slower than software virtualization. This is due to the need to emulate and control the OS of each machine.
Paravirtualization is used to improve efficiency. This is based on the fact that the guest OS is aware of what is happening inside the virtual machine and can use some of the features provided by the hypervisor. This speeds up performance because the system does not need to emulate the entire virtual machine.
KVM
Kernel-based Virtual Machine - the outstanding representative of hardware virtualization, capable of handling high server load while delivering high performance. Each VM is a separate instance of the operating system, not a module.
It can use Linux, Windows, FreeBSD or create its own distribution.
It is a relatively young virtualization, but the most promising.
Xen
KVM equivalent with identical functionality. Allows you to install any operating system on the server and use paravirtualization capabilities. Each virtual machine (VPS) is completely independent and can be moved to another host if necessary. Modern Xen is now actively oriented towards cloud technologies, which makes it even more relevant.
Hyper-V
A hardware hypervisor is a special kind of virtualization that is not as popular as other systems. But it is part of the Windows Server operating system and is not a separate product - Hyper-V can only be used in conjunction with Windows. The software is very resource-efficient, which ensures stable operation of Virtual Server.
VMWare
The leading hardware virtualization platform for Linux and Windows Server operating systems. The free version is recommended for dedicated server owners who wish to independently create virtual machines on their physical hardware. Although the free version of VMWare has some restrictions, it is still a great solution for individual use.
Selection criteria
Software hypervisors:
| Pluses | Minuses |
| Fast sweep, OS is usually not installing - unpacking a template with given parameters. | Requires an OS on which the container has access to the hardware resources of the physical server. |
| You can edit the resource configuration almost on the fly. | The load of virtual machines affects each other, the physical server OS has access to the virtual machines. |
| Unlimited overselling. Suitable for small web projects only. |
Hardware hypervisors:
| Pluses | Minuses |
| Operate in hardware with physical server emulation. | Require careful configuration of virtual machines to match physical hardware. |
| Virtual machines are isolated. | Takes a long time to deploy virtual servers, long reboot. |
| Overselling is limited by the hardware limits of the physical server. |
The choice of technology depends on the user's specific requirements in terms of performance, availability, scalability and financial costs.
Each option has its own advantages and disadvantages, but both are best for projects ranging from e-commerce to gaming platforms. Some of the advantages of virtualization include increased security, reliability, ease of use, ease of scalability and affordability.
