Greetings and salutations. In our article today, we will evaluate two virtualization technologies. Virtualization is a concept that has gained popularity over time and has become one of the leading technologies deployed in small and large organizations. In the days past, organizations spent quite a huge investment in deploying both servers and databases. As data grew in size, organizations would spend more money on getting new servers and databases. This saw their Data Centers become so small as new racks are added to the already congested Data Centers. Then the concept of Virtualization was born. Virtualization relies on software to simulate the hardware functionality and create virtual computer systems. The concept of Virtualization enables system administrators to run multiple independent virtual machines, running on independent operating systems on a single host. This way, they are able to run multiple operating systems and applications on a single server. The software that runs on top of the host server is called a hypervisor. A hypervisor completely isolates the virtual machines from the host server. There are two main types of Hypervisors i.e Bare metal hypervisor commonly referred to as Type-1 hypervisor and Hosted Hypervisor or Type-2 hypervisor. Type-1 hypervisors run directly on the host’s hardware. Type-2 hypervisors run as a software layer on an operating system on a host.

Key benefits are associated with Virtualization. These include cost efficiency, scalability, greater efficiency, high availability, and reduced storage in terms of physical space in a Datacenter. Virtual Machines running on a host server are completely isolated from the host, each with its own partitioning, it’s completely encapsulated allowing it to be converted to files that can be easily shared and they are also hardware independent.

Types of Virtualization

There are several types of Virtualization:-

Server Virtualization – In server Virtualization, multiple Operating Systems run on a single server as virtual machines. The benefits associated with this type of virtualization include:-

• Faster workload deployment.
• The server is highly available.
• Leads to reduced operating costs.
• There is increased application performance.
• IT efficiency is enhanced.
• Server complexity is eliminated.

Network Virtualization – In Network Virtualization, applications are able to run on a virtual network as though they were running on a physical network. However, on a virtual network, the applications run with greater operational benefit while leveraging on hardware independence of virtualization. In a virtualized network, we have logical networking devices and services.

Desktop Virtualization – In Desktop Virtualization, a user workstation is simulated to be remotely accessed by another remote workstation. This allows users to virtually work wherever they are as they can access the enterprise resources using a network connection.

With that background, we will now analyze two very common hypervisors i.e ESXi 9 vs Proxmox VE 9. Let’s get started.

VMware ESXi 9.0

ESXi 9.0 is a Type-1 Hypervisor. VMware vSphere 9.0 was released on 17 June 2025. VMware ESXi is the enterprise workload platform that brings the benefits associated with the cloud to on-premises workloads. The new release brings in a supercharge workload performance, enhanced operational efficiency, and accelerated innovation for DevOps.  VMware ESXi 9.0 is a proprietary virtualization management solution by VMware.

The new features on VMware ESXi 9.0 include the following.

1. The use of local NVMe devices as a secondary memory tier (beyond DRAM) to expand the effective memory available. The result would be lower costs for DRAM, higher workload density, and better consolidation of VMs.
2. Cluster Images in vSphere Lifecycle Manager (vLCM) – Improved support for heterogeneous hardware clusters. You can have multiple image configurations per cluster (for different server models/vendors) while keeping the same base ESXi version. Simplifies update/patch management across mixed hardware.
3. The ESXi 9.0 release includes support for large virtual machines, sometimes termed “monster” VMs. For example, virtual machines with up to ~960 vCPUs will be possible. Also included is support for newer CPU models (Intel, AMD). These features will allow customers to host very large workloads, like data analytics and in-memory workloads.
4. Updates to vTPM Specification – ESXi has enhanced its support for virtual TPM (Trusted Platform Module), aligning with a recent specification (for example, TPM Library Specification family 2.0 revision 1.59). This enhances the security posture for protecting virtual machines.
5. The core storage upgrades include supporting 4Kden and SEsparse snapshots. The 4K native disks help in better support for certain storage types like vSAN. Better snapshot handling through SEsparse allows faster space reclamation and lower performance penalties in the presence of snapshots.
6. Global deduplication for vSAN (ESA) – Dedup across cluster/disk groups to minimize storage waste, especially in the event of duplicates.
7. Live Patch Enhancements – Major injected of live patching so that critical patches/security fixes can be applied with minimal downtime.
8. Improvements in security/protocols: Stronger ciphers, better API/management endpoint hardening, etc. – More secure-by-default settings, better encryption, etc.

Proxmox VE 9.0

We will now turn our attention to yet another Type-1 Hypervisor called Proxmox VE 9.0. Proxmox is an open-source virtualization management solution released on August 5, 2025. Read the release documentation for more information. Proxmox Virtual Environment 9 is based on Debian 13 “Trixie” Debian 13 (Trixie), but uses a newer Linux kernel 6.14.8 and ships with QEMU 10.0.2, LXC 6.0.4, and ZFS 2.3.3.

Proxmox Virtual Environment is free and open-source software published under GNU Affero General Public License, v3. Proxmox VE 9.0 has an easy-to-use web-based user interface as well as a command line interface for management purposes.

It has wide usage with more than 450,000 hosts and has been translated into over 26 languages. It has an active community of over 65,000 members. Proxmox VE 9.0 is a non-proprietary virtualization management solution tool. For enterprise support, a subscription from Proxmox Server Solutions GmbH is available.

What’s new in Proxmox VE 9.X

The new features associated with Proxmox VE 9.x are as follows.

1. Debian 13 “Trixie” base + Linux Kernel 6.14.8 – Newer hardware support, security fixes, driver improvements.
2. Snapshots of thick-provisioned LVM shared storage – Until now, snapshots were applicable primarily for thin-provisioned or local storage. With the recent enhancement, thick LVM over SAN (iSCSI/FC) now supports snapshots, standardizing backup / snapshot workflows within enterprise SAN configuration.
3. Underlay Overlay networks are established on the off chance that you need low-standards and use it for completing opened and windows and the full frame venture topologies and use multi bolstered conditions.
4. HA Affinity Rules allow greater control over where VMs will run in HA clusters to keep certain VMs together or apart, assign preferences, reduce latency, and more.
5. Enhanced Mobile Interface (using Rust + Yew framework) gives Clusters a mobile UI to manage from mobile’s browser; better performance, touch-friendly, and redesigned UI.
6. ZFS Improvements: RAIDZ Expansion: This makes it possible to attach devices to already existing RAIDZ pools without much downtime. This will boost the scalability and flexibility of ZFS storage.
7. There should be improved metrics of observability which will include more in-depth metrics for CPU, I/O, and memory stalls. We will definitely see improved resolution of metrics over time along with support for forwarding metrics to the telemetry systems.
8. You can restore data from Proxmox Backup Server and speed improvements are done.

General Tabular Comparison.

I will now briefly give a general tabular comparison below.

Feature	Proxmox VE 9.0	ESXi 9.0
Pricing	Has a free version with limited features and a paid subscription to access technical support and enterprise repositories	Has a free version with fewer features and a paid subscription for enterprises.
Security	Proxmox supports automatic backups and advanced security features	Runs only the services essential for its operations and firewall by default to improve security. ESXi ensures the host security by securing the boot with a trusted platform module.
Ease of use	Has an integrated GUI as well as a command line interface.	ESXi 9 uses a vSphere web client for management that offers advanced features and is very user-friendly allowing system admins to create VMs very fast
Clustering	Has centralized management of multiple Proxmox servers from a single web management console. This offers Multiple authentication methods, Centralized web management, and Ease of migration for VMs and containers. Users can create clusters of up to 32 physical nodes and configure them from a single management console.	VMware vCenter is required to create ESXi clusters. The clusters allow users to get cool features such as distributed resource scheduler, high availability, vMotion, and fault tolerance. The VMs per cluster has been increased to 10000
Performance	Proxmox offers an enterprise-level utility for backing up and restoring virtual environments, hosts, and containers. The supported functionalities include Zstandard compression, authenticated encryption, deduplication, and incremental backups.	VMware ESXi offers higher host capabilities and RAM. The free version of VMware ESXi does not support file-based backups and backup solutions.
	Open source solution	Requires subscription
	A good solution for home users	Appropriate for Enterprises
Virtualization Technology	Supports two virtualization technologies i.e KVM for virtual machines and LXC for containers.	Supports KVM.
Hypervisor	Type-1 Hypervisor	Type-1 hypervisor

Feature-focused Tabular Comparison

Now, here’s a more feature-focused tabular comparison:

Category	Proxmox VE 9.0	VMWare ESXi 9.0
Base OS / Kernel	Based on Debian 13 “Trixie” with Linux 6.14.8 → latest hardware support, drivers, and security patches.	Proprietary VMware ESXi hypervisor integrated with VCF 9.0; updated kernel-level optimizations for high-density workloads.
Storage Enhancements	– Snapshots now supported on thick-provisioned LVM shared storage. – ZFS RAIDZ expansion (add disks to existing RAIDZ). – Faster restore from Proxmox Backup Server.	– 4Kn native disk support. – SEsparse snapshots (better snapshot performance & space reclamation). – Global deduplication in vSAN ESA.
Networking / SDN	– New “Fabrics” SDN feature. – Support for OpenFabric & OSPF routing protocols in SDN. – Enhanced full-mesh & redundant topologies.	– Advanced vSphere Distributed Switch (VDS) updates. – More secure/optimized NSX-T integration. – TLS 1.3 enabled by default for management & APIs.
High Availability & Clustering	– Node & Resource Affinity rules (keep VMs together/apart). – Smarter HA decisions across nodes.	– Composite Cluster Images (vLCM) → manage mixed hardware in one cluster. – Expanded live patching (apply updates with minimal downtime).
VM / Workload Support	– General improvements to QEMU/KVM guest support. – Better metrics (CPU stalls, I/O, memory).	– “Monster” VM support (up to ~960 vCPUs for massive workloads). – NVMe memory tiering (use NVMe SSDs as memory extension). – Updated vTPM 2.0 spec for guest security.
Management / UI	– Revamped mobile interface built with Rust + Yew (faster, touch-friendly). – Improved cluster metrics visualization.	– vCenter improvements with more automation hooks. – vSphere Lifecycle Manager streamlined with cluster image profiles. – Enhanced API security & management endpoints.
Security	– Improved observability and metrics for troubleshooting. – SDN-based isolation improvements.	– TLS 1.3 and stronger default ciphers. – Enhanced VM security with vTPM updates. – Stricter hardening of vCenter/ESXi APIs.
Target Audience	Geared toward open-source enthusiasts, SMBs, and enterprises seeking cost-effective virtualization with flexibility.	Geared toward large enterprises, AI/ML, and mission-critical workloads requiring advanced features, support, and ecosystem integration.

Final thoughts

Both Proxmox VE and ESXi are great Hypervisor software. Our guide has given an in-depth look at the two Virtualization environments. While Proxmox is open source, many organizations don’t fully trust open-source products and instead opt for proprietary software. For home users running small clusters, Proxmox is a good pick. Proxmox is ranked #2 as the best server Virtualization software. Personally, Proxmox is my go-to Virtualization platform for my Home lab.

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