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Best Server Virtualization Software for 2021

Server virtualization software burst onto the scene in the early 2000s. The meteoric rise of VMware came as organizations were at the outset of deploying multiple virtual machines (VMs) on one physical server. Gone are the days of low rates of server utilization and one physical server hosting one application.

Here are the top server virtualization software vendors that you should consider for your business. Whether your company values speed, cost-effectiveness, or scalability, one of these software options can serve your needs.

Best Server Virtualization Software

VMware vSphere

VMware is the vendor to beat in server virtualization with VMware vSphere. It is likely to be on all shortlists as it has dominated the market for so long. It top all competitors on overall user ratings.

But it may be a victim of its own success. The company has steadily advanced functionality to the point where it may be a little too complex for SMBs that are not tech savvy. In addition, some users believe that there are better alternatives around for Linux-heavy environments. Pricing is another area where competitors can gain ground. VMware has always offered a premium product at a premium price.

However, in large enterprise environments – with a large budget – that cross a variety of platforms, OSs and architectures, VMware remains king.

Read our in-depth review of VMware vSphere

Red Hat Virtualization

Red Hat Virtualization does well against VMware in Linux environments. It is lower cost and is said to be easier to manage. Overall user ratings are only slightly behind vSphere. While it is used by many SMBs, they tend to only be those with IT staff already experienced in open source and Linux deployments.

Overall, it is more of a tool for large deployments that require significant server density. Where Linux is preferred to Windows, Red Hat Virtualization should be on the short list.

Read our in-depth review of Red Hat Virtualization

Proxmox VE

Proxmox is a lower-cost alternative to Red Hat in Linux-rich environments. It has carved out a niche in Germany and other parts of Europe, particularly among SMBs with IT staff experienced in open source software. Its combination of server virtualization, containers and software defined storage in one product makes it especially attractive to organizations wishing to implement these technologies. It also competes closely with Virtuozzo (see below).

Read our in-depth review of Proxmox VE

Microsoft Hyper-V

Open source environments are unlikely to view Microsoft as their top choice for a virtualization platform. And it very much works the other way. Why use Linux-oriented and open-source tools to manage VMs on Windows servers? This play in Microsoft’s favor: any Microsoft or Windows shop will typically avoid open source vendors, and instead place Hyper-V on it short list.

Hyper-V scores only a little behind VMware on user ratings, but is less expensive and more tightly integrated to the entire Microsoft ecosystem. But VMware may be a better option for more environments. However, check compatibility carefully as Hyper-V has a wider range of supported hardware, and offers certain advanced features without requiring additional license fees.

Read our in-depth review of Microsoft Hyper-V

Citrix Hypervisor

Citrix Hypervisor offers an enterprise-level feature set as a low-cost virtualization platform alternative to VMware vSphere. It leads the industry in 3D graphics support, and can span both Windows and Linux workloads.

Hypervisor is graded a little behind VMware by users, but not by much. It also has a following among SMBs. For those with an existing Citrix presence, it is an attractive option. It is also a candidate where there is a large mix of Windows and Linux machines. But where one or the other of these operating systems predominates, other virtualization platforms may be a better fit.

Read our in-depth review of Citrix Hypervisor

Oracle VM Server

Oracle VM VirtualBox is clearly a good choice for Oracle application users in an x86 or AMD/Intel64 environment. Because it’s open source, skilled IT teams appreciate its flexibility and speedy performance when testing, developing, demonstrating and deploying solutions across multiple platforms from one machine. This cross-platform virtualization solution supports Windows, Linux, Mac OS X, Oracle Solaris and a variety of guest operating systems.

While it falls behind in automated conveniences and elegant interfaces compared to the competition, it makes for these drawbacks with powerful performance, flexibility, and a large library of third-party prebuilt emulated systems. The price point is also a large draw, as it’s freely available under the terms of the GNU General Public License (GPL) version 2.

Read our in-depth review of Oracle VM Server


Just as VirtualBox is the obvious first choice for Oracle apps, IBM PowerVM should be the first port of call for those seeking to virtualize AIX, IBM Linux, and IBM clients.

However, VMware, Citrix and other open source tools may also get the job done if IBM’s solution proves over-engineered. The IBM option is often used by larger enterprises with significant budgets. Small businesses deploying IBM PowerVM may be better to bring in outside help to get it up and running. The complexity of the solution requires some true expertise.

Read our in-depth review of IBM PowerVM


Virtuozzo is basically a company set up to provide commercial support for the open source Kernel-based Virtual Machine (KVM) platform. It adds a great many enhancements to KVM, which is the most popular open source hypervisor.

Those using KVM who wish enhanced functionality and support should consider Virtuozzo, as well as anyone wanting to virtualize Linux servers. Its user base is comprised of mainly small and mid-sized companies as opposed to large enterprises. Virtuozzo combines server virtualization with software defined storage and containerization. But many other vendors’ can scale better and have more features akin to VMware. SMBs should consider Virtuozo, if cost is the primary concern. But larger organizations with bigger budgets may want to look elsewhere.

Read our in-depth review of Virtuozzo

Comparison Table of Virtualization Software

ProductPlatformScalabilityOverhead %MarketCostMigrationNiche

Vmware vSphere


1,024 VMs per host

5 to 25

SMB-large enterprise

Standard: $995 per license, plus $273 per year support Enterprise Plus: $3,595 per license plus $755 per year for support

Drag and drop or command line

Market leader in virtualization
Red Hat Virtualization


up to 400 hosts

5 to 20

Highly-scaled deployments with budget constraints.

Standard: $999/per managed hypervisor socket pair each year Premium: $1,499 per managed hypervisor socket pair each year

Manually or automated

Strong in Linux environments
Proxmox VE


Up to 32 nodes per cluster

5 to 10

Hyperconverged infrastructure, Ceph Storage cluster, software-defined data center, cloud computing.

Community:$85 per year & CPU Basic:$270 per year & CPU socket Standard: $398 per year & CPU socket Premium: $796 per year & CPU socket

One click in Web interface

Lower cost provider in Linux environments
Microsoft Hyper-V


240 vCPUs per VM

9 to 12

Windows Server users, Microsoft/Azure customers

Standard: $1,323 for up to 16 cores Datacenter: $3,607 for up to 16 cores

Import/export enables easy VM move

Top offering for Windows data centers

Citrix Hypervisor


64 VMs per host

5 to 10

Citrix Virtual Apps and Desktops users, data center server consolidation, high-performance 3D graphics.

Standard: $800 per CPU socket Premium: $1,525 per CPU socket 

Can move a running VM from one host to another

Lower cost alternative, popular among SMB

Oracle VM VirtualBox


256 vCPUs per guest

5 to 10

Oracle app users


Move over secure SSL linksGeared for Oracle users and customers looking for a free, flexible solution


AIX, Linux and IBM i clients

1000 VMs on a single server

10 to 15

Virtualization for AIX, Linux and IBM i clients running IBM Power platforms

$590 per core

Move active or inactive VMsVery well suited for IBM environments



About 50 virtualization instances per server

5 to 20

KVM users, open source users, SMBs

$990 per month per business

Command line interfaceFocused on open source

Your Guide to Server Virtualization Software

Server virtualization software continues to show promise for organizations who need flexible, digital solutions. With evidence of reduced costs, scalability, and great control optimizing performance, it’s hard not to consider virtualization software. We look at what server virtualization is, how it works, considerations for buying, and the market at-large.

Also Read: Software-Defined Networking (SDN) Advantage

What is Server Virtualization?

Most people imagine rows of bustling, physical machines when they hear the word servers, but the reality for many personnel today is managing servers virtually on a single physical server.

Just like its hardware counterpart, server virtualization contains the same functionality and performance as a physical server. As a network layer, virtualization is the software-based process of taking physical machine attributes and abstracting them into virtual assets.

Though server virtualization software is a digital solution, a physical host server is still necessary.

Also Read: Virtualization and the Dynamic Enterprise

Why Do I Need Virtualization Software?

Before the innovation of server virtualization, servers were implemented the world over for business-critical applications. Sadly, too many of these servers sat idly, using minimal storage and memory and not maximizing processor capabilities. Going without some form of server technology for most organizations wasn’t an option, and there lies the difficulty.

Organizations have a flexible, less expensive solution for using server bandwidth needed by implementing server virtualization software.

Also Read: Storage Virtualization to Continue on Growth Trajectory

What Does Server Virtualization Do?

Virtualization software employs a divide and conquer method to tackle individual tasks and workloads. The result is the ability to execute application workloads independent of the physical server and a cluster of server assets. For a user, this means managing multiple computers or virtual machines (VMs) on their physical device without wasting resources on physical server deployment.

What Is a Virtual Machine (VM)?

The result and benefit of implementing virtualization are enabling the use of virtual machines. Like any other computer, a virtual machine contains an operating system, CPU, memory, and storage. VMs reside and borrow resources from a single-host server. In the age of cloud computing, the demand for VMs as an alternative to physical servers is stronger than ever.

Also Read: How Virtualization Exacerbates Fragmentation

Four Properties of Virtualization

IsolationProvides security isolation and preserves performance
PartitioningRuns multiple OS and divides resources between VMs
EncapsulationSaves VM state to files for easy copy or transfer
Hardware independenceProvision or migrate any VM to any physical server

What is a Hypervisor?

Unless your organization is deploying OS-level virtualization, a hypervisor is crucial to deploying server virtualization. The hypervisor runs above the physical host and serves as a middleman for passing resources to VMs. Hypervisors come in two types:

  • Type 1: Installed directly on top of the physical server, also known as bare metal hypervisors
  • Type 2: Similarly installed on top of the physical server, a host OS sits between the host and the hypervisor

Type 2 hypervisors are less common but are used for end-user virtualization. By comparison, Type 1 is considered more secure and offers lower latency, making it the preferred choice of most server administrators.

Also Read: Intel, VMware Sign Virtualization Pact

Approaches to Server Virtualization

Full virtualization: Hypervisor – Organizations going full virtualization deploy a hypervisor to build and maintain autonomous VMs that are cross-OS compatible. This hardware-assisted method for virtualization is the leading implementation method and products include Microsoft Hyper-V, Oracle VM VirtualBox, and VMware vSphere.

Paravirtualization: Add an API – Like full virtualization, paravirtualization (PV) uses a hypervisor and includes an application programming interface (API) that communicates between the hypervisor and the operating systems. Most organizations deploying full virtualization also enable PV.

OS-level virtualization: No hypervisor – Without a hypervisor, the physical server’s OS becomes the virtualization central and creates multiple user environments referred to as containers. In this approach, an OS kernel can create the segmentation necessary within the host server so that no hypervisor is needed to transfer resources.

Virtualization Software Benefits

  • Lower operating costs. When organizations adopt virtualization, an indisputable benefit is a cost and resource savings. As physical servers become less critical to SMB organizations and the virtualization software market grows, more firms will jump at the opportunity to save on overhead, electricity, and maintenance costs. Resource savings include the time and labor devoted to on-premises servers and the physical infrastructure footprint now available.
  • Faster workload deployment. Server virtualization software is known for being quick and easy to deploy. Specifically for developers, spinning up servers offers faster provisioning of applications and resources. This boost means increased agility for the IT team in managing the performance and responsiveness of the infrastructure. With a suite of VMs at an organization’s disposal, server administrators can spread processing resources across VMs to ensure optimized performance.
  • More resilient. Virtual machines have incredible portability and the security needed to analyze, detect, and protect against threats. When utilizing a hypervisor, administrators can move VMs almost instantaneously to another hypervisor, offering redundancy, disaster recovery, reduced downtime, and points to the speed at which VMs can be deployed or transferred. Advanced security tools like sandbox capabilities are being adopted for VMs and offer an isolated environment for malware analysis.

Also Read: Virtualization Tools Power Up

Virtualization Software Considerations

For server virtualization software, the right solution depends on whether the tool reflects a company’s unique business needs and goals. Here are a few factors to consider.

  • Supported operating systems: The first thing to consider is each software’s supported OS. While top market vendors can offer cross-OS compatibility, many also only serve a specific OS, such as Windows, Mac, or Linux. IT organizations and developers, in particular, are responsible for testing programs and compatibility between OSes. Without virtualization, the ability to test and utilize programs against heterogeneous OSes diminishes.
  • Virtualization software scalability: For cloud and hybrid organizations, virtualization software also offers scalability to support a fluctuating number of users and the ability to deploy new features quickly. Scaling out would mean adding additional hardware and software to meet the needs of new applications or more robust storage. Scaling up means server administrators can increase memory, bandwidth, and CPU cores to manage larger workloads. Direct use of the cloud for virtualization means the added scalability that only cloud service providers can offer.
  • Reduce resources with virtualization: Server buyers should consider solutions that consume less memory. If the RAM‘s system is limited, the extra resource usage needed to support a robust virtualization tool can seriously slow down a system. This predicament could lead to spending more money on upgrading hardware, and if the price is the primary concern, there are solid free virtualization options available fit for smaller teams.

Also Read: Virtualization vs. Containerization

The Server Virtualization Software Market

Market Trends. According to Market Research Future, the server virtualization market is expected to grow up to $8 billion by 2023, at a 7% CAGR between 2017 and 2023. That represents a market that will almost double in that time.

Market Vendors. While VMware remains the market leader, alternatives from Microsoft, Red Hat, Citrix, Oracle, Proxmox, IBM, Virtuozzo, and others offer plenty of competition. Those companies provide a slew of features that have given new life to virtualization. The latest generation of products incorporates features for the cloud, containerization, hyper-convergence, and software-defined computing.

Also Read: Dell Joins Server Virtualization Fray

Virtualization Software: Flexible and Resilient

Server virtualization software offers organizations a flexible, resilient solution for managing extensive operations without the physical infrastructure. From lower operating costs to scalability and workload optimization, server virtualization is a solution in demand. We look forward to seeing the continued development of virtualization technology regarding server power and informing you of our top picks.

Also Read: Scalent Scales Virtualization Management to New Heights

ServerWatch‘s Best Virtualization Software Methodology

Our best server virtualization software methodology is based on independent analysis, user reviews, pricing data, vendor information, analyst reports, use cases, and market trends.

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