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VMware ESXi has been a key player in the virtualization space for over two decades, evolving from its ESX origins into the type-1 hypervisor we know today. This post traces its development from the early ESX releases to the current ESXi 8.0 focusing on the technical milestones and features that have shaped it.
Here is my in-depth rundown, paired with a handy table for quick reference.
The Early Days
ESX 1.0 launches in 2001 with basic VM support. It handles Windows and Linux guests simply. Then, ESX 2.0 arrives in 2003 and improves performance. It also supports more hardware. Meanwhile, ESX 2.1 follows in 2004 to refine stability. By 2005, ESX 2.5 introduces 64-bit guest support. Additionally, it enhances storage management.
Next, ESX 3.0 rolls out in 2006 and brings vMotion. This allows live VM migration without downtime. Furthermore, vCenter Server centralizes management. Later, ESX 3.5 debuts in 2007 and supports 64-bit hosts. It adds Storage vMotion too. Moreover, vSphere HA ensures VM recovery during failures.
The Shift to ESXi
ESX 4.0 releases in 2009 with vSphere 4.0 features. It introduces the vSphere Distributed Switch for networking. Similarly, it enhances backups with vSphere Data Protection. Patching streamlines through Update Manager. However, ESXi 4.1 marks a shift in 2010. The Service Console is removed for a leaner design. Consequently, this boosts security and performance.
Mid-Stage Developments
ESXi 5.0 launches in 2011 with vSphere 5.0. It introduces VAAI to offload storage tasks. Meanwhile, Storage DRS balances datastores automatically. VMotion refines for smoother operation. Then, ESXi 5.1 appears in 2012 and boosts scalability. It also adds vSphere Replication for disaster recovery.
Later, ESXi 5.5 emerges in 2014 and supports early containers. It implements Network I/O Control 3 too. Plus, it enhances HA and DRS for clusters. By 2015, ESXi 6.0 introduces Virtual Volumes. This improves storage flexibility significantly. Additionally, OpenStack integration aligns with cloud trends.
More Recent Iterations
ESXi 6.5 releases in 2016 and brings Lifecycle Manager. It centralizes host management effectively. Furthermore, Distributed Services Engine offloads tasks. NVMe support speeds up storage. Then, ESXi 6.7 arrives in 2018 and refines Lifecycle Manager. It expands hardware compatibility too.
In 2020, ESXi 7.0 launches and integrates Kubernetes. It supports containers natively. Surprisingly, it enables ARM hosts, breaking from x86 norms. The Distributed Services Engine upgrades as well. Finally, ESXi 8.0 arrives in 2022. It introduces DPU offloading to ease CPU loads. Accordingly, it enhances security and performance.
ESXi Major Version and Feature Table
| Version | Release Date | Notable Features |
|---|---|---|
| ESX 1.0 | 2001 | Basic VM support added |
| ESX 2.0 | 2003 | Performance improved |
| ESX 2.1 | 2004 | Stability refined |
| ESX 2.5 | 2005 | 64-bit guests supported |
| ESX 3.0 | 2006 | VMotion introduced |
| ESX 3.5 | 2007 | vSphere HA added |
| ESX 4.0 | 2009 | vDS implemented |
| ESXi 4.1 | 2010 | Service Console removed |
| ESXi 5.0 | 2011 | VAAI introduced |
| ESXi 5.1 | 2012 | vSphere Replication added |
| ESXi 5.5 | 2014 | Containers supported |
| ESXi 6.0 | 2015 | VVOLs introduced |
| ESXi 6.5 | 2016 | Lifecycle Manager added |
| ESXi 6.7 | 2018 | Hardware support expanded |
| ESXi 7.0 | 2020 | Kubernetes integrated |
| ESXi 8.0 | 2022 | DPU offloading enabled |
Controversies Along the Way
Some bumps have been hit by ESXi. For instance, the Service Console was dropped in ESXi 4.1. Workflows were disrupted for many admins. In 2011, vRAM limits were imposed with vSphere 5.0. User backlash was swift, and the model was adjusted later.
The vSphere Flash Client, introduced around ESXi 6.0 in 2015, quickly became a sore spot for users. Initially, it aimed to modernize the interface but frustrated admins with sluggish performance. Moreover, frequent crashes disrupted workflows significantly. Security vulnerabilities tied to Flash also raised concerns, as Adobe’s platform was already on shaky ground. Consequently, VMware phased it out by ESXi 6.7, shifting to the HTML5 client.
Recently, Broadcom’s 2023 acquisition raised concerns. Subscription-only licensing was pushed for ESXi 8.0, upsetting smaller users. Security issues were exposed too, like the 2021 ransomware wave tied to CVE-2021-21974. Patching delays were criticized heavily.
Final Thoughts
Steady progress has been made by ESXi over the years. The introduction of vMotion was a significant turning point (and it certainly set my career path!) Similarly, container support in 7.0 showed adaptability. Yet, controversies like licensing shifts have left marks. As of March 2025, ESXi 8.0 is maintained with updates. Its role in virtualization remains solid. I’m excited to see what Broadcom do with the hypervisor in the years to come!
Learn more about ESXi versioning at Broadcom’s Knowledge Base.
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