What is VPS Virtualization? KVM vs OpenVZ vs Xen: Which is Best for Server?

Are you looking for a suitable VPS virtualization technology? The most popular ones in the current market are KVM, OpenVZ, and Xen. The choice of virtualization technology directly impacts the performance and efficiency of your server. Which one is right for you? You need to find the answer to this question: Who wins in the better of KVM vs OpenVZ vs Xen?

Let’s begin the comparison to discover the correct answer!

What is Virtualization?

vps virtualization

Virtualization is the foundation of cloud computing. It uses software to create an abstraction layer of several virtual instances on a physical server. Thus, you can utilize the physical computer hardware more efficiently. You can divide the elements of a single computer, like the storage and memory, into multiple Virtual Machines.

Virtualization brings several benefits, including:

Resource efficiency: Virtualization maximizes hardware utilization by running multiple apps on one server.

Easier management: Software-defined VMs simplify IT tasks and automate workflows.

Minimal downtime: Redundant Virtual Machines offer failover solutions to reduce user disruption.

Faster provisioning: Virtual machines speed up application deployment with workflow automation.

Today, virtualization is a standard practice that revolutionizes web hosting by enhancing resource utilization and scalability of the IT infrastructure.

Virtualization in Web Hosting: What is VPS Virtualization?

VPS virtualization has become the standard for web hosting. It represents the technology that most VPS hosting providers follow. In VPS hosting, users get shared resources running as Virtual Machines over a Dedicated Virtual Private Server. So, users enjoy greater control over the machine and the overall software stack.

Virtual Private Server virtualization technology has become immensely popular due to its cost-effectiveness and versatility. It utilizes a hypervisor to create virtual instances known as hosts. Each of these instances is a Virtual Private Server. It acts as an independent entity with dedicated resources.

Now, you can choose between the virtualization technologies - KVM, OpenVZ, and Xen. But which technology offers what? Let’s find out!

What is VPS KVM Hosting Technology?

kvm virtualization

KVM (Kernel-based Virtual Machine) is a hardware-assisted virtualization technology that leverages the Linux kernel to create and manage virtual machines. Each KVM VPS operates independently, benefiting from dedicated resources and full virtualization of the underlying hardware. Kernel-based Virtual Machine hosting is known for its exceptional performance and reliability.

Storage KVM VPS Options:

If you prioritize storage capacity or speed, KVM hosting is what you need! Kernel Virtual Machine offers a range of storage options, including traditional hard drives and cutting-edge solid-state drives. SSD KVM VPS, in particular, delivers exceptional data access speed. It is ideal for applications that demand high-performance storage.

Advantages of KVM VPS:

   It offers high performance, perfect for resource-intensive applications.
   It provides access to dedicated, high-speed storage options for improved data access.
   Ir utilizes solid-state drives for lightning-fast data retrieval and reduced latency.
   VPS KVM hosting ensures complete isolation, enhancing security and stability.
   You can do live migration of virtual machines between host servers without downtime.
   KVM supports different operating systems, including various Linux distributions and Windows.

Disadvantages of Kernel Virtual Machine:

   KVM can be resource-intensive and requires more hardware capabilities.
   It may be less cost-effective for small-scale applications due to higher resource allocation.

What is an OpenVZ Virtual Server?

openvz virtualization

OpenVZ Virtualization is known as Open Virtuozzo. It is a container-based virtualization technology. It deploys separate OS instances on a web server by sharing the same OS kernel. Each container is a distinct Linux system with root privileges and IP addresses.

Unlike KVM, OpenVZ Virtual Server shares the host kernel among virtual environments. It is a more lightweight solution than other available virtualization technologies. Each OpenVZ server operates within these containers that share the host's kernel and system resources. It doesn't introduce overhead like traditional hypervisors. It offers faster performance with no downtime for various Linux-based operating systems.

Advantages of Open Virtuozzo

   OpenVZ is a lightweight and cost-effective choice for smaller projects.
   It offers good performance for applications with lower resource requirements.
   It promotes efficient resource usage and saves CPUs and memory.
   It is easy to configure and manage without any technical knowledge.
   Each container per VPS is affordable with a shared OS kernel.
   Low memory footprint benefits limited memory VPS.
   Suitable for those with minimal requirements and less overhead.

Disadvantages of OpenVZ Virtual Server

   The shared kernel can lead to security and stability concerns in multi-tenant environments.
   Resource allocation can be less predictable, which affects the VPS performance.
   You cannot manually introduce your OS during the single working framework.

What is Xen?

xen virtualization

Xen VPS virtualization is a hypervisor-based virtualization technology. It is perfect for creating and managing virtual machines on Virtual Private Servers. Xen takes a middle ground between KVM and OpenVZ, offering better isolation than OpenVZ but less heavy than KVM. It is popular among hosting providers for its flexibility and performance.

Advantages of Xen

   Balances performance and security that suit various mission-critical applications
   Predictable resource allocation with guest OS to run in hardware virtualization mode
   Minimal code for enhanced stability with essential functions separated from the hypervisor
   Open-source nature allows for extensive product modification and customization
   Cross-platform support for various architectures with increased versatility
   High-speed performance and complete resource isolation for productive virtual machines
   Efficient migration of virtual machines without the need to halt work processes
   Proven stability through years of development and consistent flawless operation

Disadvantages of Xen

   Xen may not be as resource-efficient as OpenVZ for smaller projects.
   Setting up Xen VPS may require more technical expertise than KVM VPS or OpenVZ.

KVM vs OpenVZ vs Xen: Exploring The Differences

kvm vs openvz vs xen

When choosing the right virtualization technology, understanding the differences between KVM, OpenVZ, and Xen is crucial. These technologies diverge on several key aspects. Let's delve into the distinctions among these popular virtualization options.

Level of VPS Virtualization

Kernel-based Virtual Machine (KVM) offers full virtualization. Each VPS operates as an independent virtual machine with its OS. This provides a high level of isolation and security.

OpenVZ employs OS-level virtualization by sharing the same kernel with the host. While it's efficient, it offers a lower isolation level than KVM.

Xen strikes a balance by offering a middle ground between KVM and OpenVZ. It provides more substantial isolation than OpenVZ but doesn't require full emulation like KVM.

Overselling of Resources

KVM VPS hosting typically avoids overselling resources, ensuring consistent user performance but often at a higher cost.

OpenVZ is more prone to overselling, where providers allocate more resources than the host server possesses. It can lead to variable performance.

Xen providers have more flexibility and control over resource allocation, allowing them to manage it efficiently.

Types of Memory: Is SSD KVM VPS Better?

KVM VPS can use both swap space and RAM for memory. It offers more flexibility and better performance. OpenVZ employs a different memory management model. It also uses a combination of RAM and swap that may affect application performance differently. Xen also offers memory handling similar to KVM, with the flexibility to utilize both RAM and swap space.

Types of OS Support

KVM supports various operating systems, including Linux distributions, Windows, and more, providing broad compatibility. OpenVZ virtual server primarily invests in Linux-based, which may limit its usability for specific applications. Xen is versatile and supports various operating systems like Linux distributions and Windows.

Processing Delays

KVM's hardware virtualization can introduce slight processing delays due to emulation. But it provides strong isolation. OpenVZ has minimal processing delays because of its lightweight container-based approach. Xen offers a good balance with acceptable processing delays while maintaining strong isolation.

Comparing The Costs

KVM is known for its high performance but often comes at a higher cost, making it ideal for businesses with demanding requirements. OpenVZ virtual server is a cost-effective choice for those on a budget, but it may compromise resource consistency. Xen balances cost and performance, making it suitable for various applications.

Community Type

KVM has a broad community and industry support. It is a reliable choice with extensive documentation and resources. OpenVZ has a more niche community, which can impact the availability of support and resources. Xen benefits from a stable and supportive community by balancing KVM and OpenVZ regarding support.

Which One Should You Choose?

choose virtualization

When comparing KVM vs OpenVZ and Xen, the choice depends on your specific VPS Hosting needs. Here is a table-view prepared for you so that you can compare them on your own:

Aspect KVM OpenVZ Xen
Virtualization Approach Full virtualization with high isolation OS-level virtualization with lower isolation Balanced isolation and no full emulation
Resource Allocation Strategy Avoids overselling and consistent performance Prone to overselling with variable performance Flexible resource allocation and efficient management
Memory Management Model Uses both RAM and swap, elastic. Combines RAM and swap may affect performance. Similar to KVM, it utilizes both RAM and swap.
Operating System Support Supports various OS, broad compatibility. Primarily Linux-based with limited usability. Versatile, supports multiple OS, including Windows.
Processing Efficiency There are slight delays due to emulation with solid isolation. Minimal delays, lightweight container-based. Balanced delays that maintain strong isolation.
Cost-Performance Ratio High performance with higher cost. Cost-effective and may compromise consistency. Balances cost and performance, suitable for various applications.
Community Engagement Broad community with extensive support. Niche community with limited support. Stable community with balanced support.
So, what does this chart highlight? Who wins as the best Virtualization Technology?

KVM VPS excels in performance and security. This VPS technology is the way to go if you need the utmost performance and reliability.

OpenVZ may offer a cost-effective solution for smaller projects with budget constraints. However, you may need more support regarding resource isolation.

Xen sits comfortably in the middle. It balances the performance and security requirements. So, it is suitable for various web applications.

However, you should do more research about these virtualization technologies before deciding.


VPS virtualization technologies are evolving fast. The choice between VPS KVM hosting or OpenVZ and Xen is yours to make! Hopefully, you now clearly understand what virtualization technology has to offer you. Hence, choose a technology that fits with your VPS Hosting needs. Hover through the advantages and disadvantages of these virtualization technologies to reconfirm your choice!
Rashmi Debnath

Hi, I'm Rashmi D., a passionate content writer with 10+ years of expertise. By profession, I'm a cloud Architect who enjoys translating complex technologies into reader-friendly technical blogs and articles. I enjoy exploring and testing new trends and the latest tech inventions. Let's discover what's happening in the tech world together through my writings!