Xen or Virtuozzo: How does virtualization differ in comparison?

The Virtualisation of Operating Systems has become a standard in a variety of IT environments, offering the performance and functionality of dedicated hardware at low costs. In the field of web hosting, Virtuozzo and Xen are among the most widely used solutions due to their efficiency, stability, and security, providing a hypervisor as an administrative instance for virtual servers or resources available in the cloud. Both applications are utilised by large market leaders, small and medium-sized enterprises, or specialised providers. However, they employ different abstraction techniques at the technical level, each resulting in specific advantages and limitations.

How does Virtualisation work and what are its benefits?

The Virtualisation of Operating Systems as servers for the internet is based on the high performance of modern hardware, offering numerous benefits to both providers and customers. Its use allows for the provision of individual environments at low costs and optimises the load distribution of single or interconnected systems. When deployed, software as an administrative hypervisor creates isolated IT environments and allocates computing power to different subsystems. The available resources can be present on a single dedicated server or distributed decentralised in a cloud. Both Virtuozzo and Xen use a virtualisation technique that does not simulate fully independent hardware but rather enforces a strict separation of individual environments under a shared kernel at the software level.

What are the advantages of Virtuozzo as a hypervisor?

Due to its good performance and high flexibility, many web hosts use Virtuozzo for a majority of the virtual servers they offer, especially in the lower price ranges for Linux VPS hosting with small to medium performance. The high popularity and distribution are mainly due to the above-average efficiency of the available computing capacities that Virtuozzo achieves through the use of tightly isolated containers, avoiding computationally intensive customisation of collective core processes. Some of the key features of Virtuozzo include:

• Very high efficiency in utilising physical hardware
• Isolation and separation of individual IT environments through containers
• Utilisation of a single central kernel for all environments
• Virtualisation is limited to the server's operating system
• Limited access to system-critical processes or configurations
• Functionality largely equivalent to more complex solutions
• Suitable for various uses including web servers
• Excellent performance at low costs

More about Virtuozzo servers and some providers of server solutions:

Compare Virtuozzo VPS hosting providers

What are the benefits of virtualisation with Xen?

Originally developed as a scientific project at the University of Cambridge, Xen has established itself since its release in 2003 as a popular and versatile hypervisor for operating system virtualisation. Like many alternative providers including Virtuozzo or VMWare, the initial purpose was to provide specialised IT environments for software development. Technically, the isolation is based on a strict separation of the individual instances by the hypervisor, which controls and coordinates the direct access to the hardware. Key features of Xen as a hypervisor include:

• Utilisation of a single kernel for all operating systems
• Direct access to physical hardware without emulation
• Hypervisor does not support virtualisation of foreign operating systems
• Instances are not connected to each other and are invisible
• Good performance and efficient distribution of computing power
• Extensive configuration of individual instances possible
• Enables uninterrupted prioritisation and allocation of computing resources

More about Xen servers and some providers of server solutions:

Compare Xen VPS hosting providers

How do Virtuozzo and Xen compare in a direct comparison?

Due to its low cost and high flexibility, Virtuozzo has a high market share as a hypervisor for cost-effective virtual Linux servers and is particularly suitable for small businesses or individuals who desire a functional and customisable web server. However, the use of containers restricts access to the core areas of the operating system. Xen, on the other hand, allows for flexible load distribution and also enables fixed allocation of resources such as memory, ensuring a consistent baseline performance for the subsystem. This increases the hardware requirements but makes the hypervisor an excellent choice for virtual servers used for commercial purposes that require fast data processing at all times and a low Server Response Time (SRT).

Our article is based on our own experiences and research, as well as information from external sources.

References & further links on the topic:
https://www.virtuozzo.com/ (Official Virtuozzo website)
http://download.parallels.com/doc/pvc/PVC_DataSheet_Ltr_EN.pdf (Information on Parallels Virtuozzo Containers)
https://xenproject.org/ (Official Xen Project website)
https://www.linux-magazin.de/ausgaben/2017/12/xen/ (Article on Xen in Linux Magazin)

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