Citrix Alternative Open Source: Which is the Best Fit?

Over the last couple of decades, server virtualization—the process of allocating virtual computing resources to operating systems (OSs) and applications rather than dedicating them to a special server—has become a fundamental principle in datacenter design. Enterprises can use server virtualization to reduce IT expenses and enhance disaster recovery measures while improving efficiency and productivity.

Citrix Hypervisor—previously called XenServer—is an open-source, type 1 hypervisor that supports server virtualization in Windows and Linux OSs. Citrix also offers other versions that organizations can purchase with Standard and Enterprise options. However, Citrix Hypervisor isn’t the only solution on the market when it comes to open-source hypervisors. In this article, we’ll explore more about top Citrix alternative open-source hypervisors.

Oracle VirtualBox

Oracle VirtualBox—previously called Sun VirtualBox and Sun xVM VirtualBox—is an open-source, type-2 hypervisor developed by Oracle Corporation. The product underwent multiple iterations through mergers and acquisitions before Oracle became its official sponsor in 2010.

Oracle relies on the GNU General Public License (GPL) and an optional Common Development and Distribution License (CDDL) for most files of the source distributions. It has different versions for various OSs, including Windows, macOS, and Solaris. IT administrators can leverage the product to run multiple OSs inside several virtual machines (VMs) simultaneously.

Oracle VirtualBox also provides multi-generation branched snapshots that IT administrators can use to revert VMs to their previous states. IT teams can also use this feature to create alternative virtual machine configurations with a snapshot. Besides multi-generation branched snapshots, Oracle VirtualBox also provides:

Guest additions. IT teams can use this feature to improve performance.
Guest multi-processing. The hypervisor can present up to 32 virtual processors to each VM, regardless of the number of processor cores that are physically present on the host.
Full Advanced Configuration and Power Interface (ACPI) support. IT teams can use this feature to clone disk images from physical machines or third-party VMs.
Multi-screen resolutions. Oracle VirtualBox’s VMs can spread over many screens attached to the physical host.
Built-in Internet Small Computer Systems Interface (iSCSI) support. This feature allows IT users to connect VMs directly to an iSCSI storage server without using the host system.

Microsoft Hyper-V

Hyper-V is Microsoft’s server virtualization technology that you can use to create VMs and run multiple OSs on a single Windows-based machine. There are three versions of Hyper-V available:

Hyper-V for Windows Server. This is a hypervisor that you can use as an add-on to the Windows Server OSs.
Hyper-V Server. This is a standalone hypervisor that you can use to manage dedicated and virtual server instances.
Hyper-V for Windows 10. This is a version of the hypervisor that runs on typical desktops or laptops.

Hyper-V relies on second-level address translation (SLAT) mechanisms available on 64-bit processors to work. The physical host must have at least 4 GB of RAM to run three to four basic VMs. However, to provision more VMs on a single server, you’ll need a server with more processing capabilities.

Below are some features of Hyper-V:

Hyper-V Replica. You can replicate VMs to different physical sites and provide higher availability and quick restoration after a disaster.
Integration services. Hyper-V can support various guest OSs by leveraging customized services and drivers.
Migration features. Hyper-V has a live migration feature that IT teams can use to move VMs from one host to another without suspending the running applications.
Shielded VMs. This feature uses the BitLocker technology to secure VMs from malware attacks and data-tampering attempts.

Proxmox Virtual Environment

Proxmox Virtual Environment—also called Proxmox VE or PVE—is an open-source, bare-metal hypervisor for enterprise virtualization. It is essentially a Debian-based Linux distribution that IT teams can use to run Windows and Linux OSs on a single machine or clusters of computers.

It also provides powerful Kernel-based virtual machines (KVMs), which provide full virtualization and lightweight Open Virtuozzo (OpenVZ). OpenVZ is an operating system-level virtualization technology in Linux that allows the server to run containers and virtual private servers (VPSs).

Proxmox Virtual Environment is fully open under GNU Affero General Public License (AGPL) version 3. As such, users can view, modify, and even distribute their own versions of Proxmox Virtual Environment freely as long as they are fully compliant with the license. Below are some features that you’re likely to get with Proxmox Virtual Environment:

High availability. Proxmox Virtual Environment can move the remaining VMs to healthy hosts to ensure minimal service disruption when one host fails.
Bridged networking. Proxmox Virtual Environment allows users to create private networks between VMs.
Flexible storage. Proxmox Virtual Environment supports various storage technologies, including Logical Volume Manager (LVM), Network File System (NFS), Gluster filesystem, and iSCSI.
Command-line interface (CLI) tools. Proxmox Virtual Environment allows users to access VMs and containers via CLI management tools.

Kernel-based Virtual Machine

Kernel-based Virtual Machine (KVM) is an open-source hypervisor infrastructure built for Linux OS kernels. While it was designed primarily for x86 processors, KVM has evolved to incorporate other architectures such as PowerPC and Advanced RISC Machines (ARM). Red Hat, Inc. is the company that builds and maintains KVM.

The KVM architecture implements each VM as a regular Linux process. Users can run multiple guest OSs, each running a different operating system image in KVM. Each of these VMs has private and virtualized hardware in a KVM architecture, allowing users to benefit from all the Linux OS kernel features.

KVM supports many operating systems, including Berkely Software Distribution (BSD), Windows, Solaris, ReactOS, Haiku, and Plan 9 from Bell Labs. In addition, a modified version of Quick Emulator (QEMU) can use KVM to run macOS platforms.

Parallels RAS: A Cost-Effective Citrix Alternative Solution

Parallels® Remote Application Server (RAS) is an all-in-one, single-license virtual desktop infrastructure (VDI) product that businesses can use to publish their virtual workspaces to any device on any platform. Organizations can use Parallels RAS to deliver full-featured Windows applications and desktops in deployments that use VMware ESXi and Microsoft Hyper-V hypervisors.

Parallels RAS also supports major hyper-converged infrastructure (HCI) solutions such as Scale Computing HC3, Nutanix Acropolis, and HPE SimpliVity. IT teams can use this combination to deliver on-demand virtual workloads securely and cost-effectively.

Most importantly, Parallels RAS is a cloud-ready platform that supports private, public, and hybrid cloud environments. It also integrates with Azure Virtual Desktop, allowing IT teams to manage and unify all enterprise resources seamlessly from a single console.

Discover why Parallels RAS is a cost-effective Citrix alternative solution!

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