As organizations continue modernizing their infrastructure with VMware Cloud Foundation (VCF) and vSphere, keeping track of guest operating system support is essential for maintaining compatibility, security, and operational efficiency. With the release of VCF 9.1 and ESX 9.1, VMware introduces support for several new operating systems while retiring support for a number of legacy platforms.
In this article, we'll explore the latest guest OS support updates, highlight deprecated and terminated operating systems, and examine a new VMware Tools enhancement designed to simplify virtual machine lifecycle management.
Guest Operating System Compatibility in ESX 9.1
Before deploying or upgrading workloads, administrators should always verify operating system compatibility against the official Broadcom Compatibility Guide. This remains the authoritative source for validating supported guest operating systems on ESX 9.1.
The latest release expands support for several modern operating systems, ensuring customers can take advantage of current platform innovations while maintaining VMware's enterprise-grade virtualization capabilities.
Newly Supported Guest Operating Systems
ESX 9.1 introduces support for the following major operating system releases:
Ubuntu 26.04 LTS
Canonical's latest Long Term Support release joins the supported guest OS list, providing organizations with a stable Linux platform backed by extended support and security updates.
SUSE Linux Enterprise Server 16
SUSE customers can now deploy and virtualize workloads on the latest version of SUSE Linux Enterprise Server, enabling access to new features and performance improvements.
Debian 13.0
Debian remains a staple operating system in many enterprise and development environments. The addition of Debian 13.0 ensures continued support for organizations leveraging this highly reliable Linux distribution.
FreeBSD 15.0
For environments running FreeBSD workloads, ESX 9.1 now supports FreeBSD 15.0, helping organizations modernize while maintaining compatibility with VMware infrastructure.
Pardus 25.0
Pardus, the Linux distribution widely adopted within various public sector and enterprise environments, is now officially supported in ESX 9.1.
CentOS Stream 10 (Technology Preview)
CentOS Stream 10 support is available as a Technology Preview, allowing customers to evaluate and test workloads running on this platform. As with all preview features, administrators should carefully assess suitability before using it in production environments.
VMware Cloud Foundation 9.1 Additions
In addition to the ESX 9.1 guest operating system updates, VCF 9.1 introduces:
CentOS Stream 9 (Technology Preview)
Organizations still operating on CentOS Stream 9 can continue their testing and validation efforts under VCF 9.1 through Technology Preview support.
This provides a bridge for customers evaluating migration paths while maintaining access to newer CentOS Stream releases.
Operating Systems Reaching End of Support
While new operating systems are being introduced, VMware is also removing support for several aging platforms. This is an important consideration for organizations planning upgrades to ESX 9.1 or VCF 9.1.
Terminated Support
The following guest operating systems are no longer supported:
- Red Hat Enterprise Linux (RHEL) 4.x
- Oracle Linux 5.x
- CentOS 4.x
- CentOS 5.x
- SUSE Linux Enterprise Server 10 SP4
- SUSE Linux Enterprise Desktop 12
- Debian 7.x
- Flatcar Container Linux 3033 LTS
- Asianux 3.x
Organizations still running workloads on these platforms should prioritize migration strategies to supported operating system versions to maintain vendor support and reduce security risks.
Deprecated Support
The following operating system remains supported for now but is marked for future removal:
- Asianux 4.x
Deprecation serves as an early warning for administrators to begin planning migration efforts before support is completely withdrawn in future releases.
Improved Visibility for Windows VM Reboots
One of the most practical enhancements in VCF 9.1 comes through VMware Tools 13.1.0.
Windows Guest OS Pending Reboot Reporting
After upgrading VMware Tools within a Windows virtual machine, administrators have traditionally needed to track reboot requirements manually or rely on in-guest monitoring. VMware Tools 13.1.0 addresses this challenge by introducing a new pending reboot status indicator.
The feature provides:
- A visual reboot status within the vCenter user interface.
- API access to reboot status information.
- Improved visibility of virtual machines requiring a restart after VMware Tools upgrades.
- Better scheduling and planning of maintenance windows.
- Reduced operational overhead for large-scale environments.
For organizations managing hundreds or thousands of Windows virtual machines, this enhancement can significantly streamline upgrade operations and improve overall maintenance efficiency.
Why These Changes Matter
The guest operating system updates in VCF and vSphere 9.1 reflect a broader industry trend: supporting modern, secure operating systems while retiring legacy platforms that no longer meet enterprise requirements.
Key benefits include:
- Access to the latest Linux and FreeBSD releases.
- Improved compatibility for modern application workloads.
- Enhanced security through the retirement of end-of-life operating systems.
- Better operational visibility with VMware Tools reboot reporting.
- Simplified lifecycle management across virtualized environments.
Final Thoughts
VCF 9.1 and ESX 9.1 continue VMware's focus on delivering a modern virtualization platform that supports current operating system releases while helping organizations phase out legacy environments.
The addition of operating systems such as Ubuntu 26.04 LTS, Debian 13.0, SUSE Linux Enterprise Server 16, and FreeBSD 15.0 demonstrates VMware's commitment to enabling modern workloads across diverse environments. At the same time, the retirement of older platforms serves as a reminder that infrastructure modernization is an ongoing process.
Combined with the new Windows Guest OS Pending Reboot Reporting capability in VMware Tools 13.1.0, VCF 9.1 provides administrators with better visibility, improved lifecycle management, and enhanced operational efficiency for today's virtualized data centers.
For customers planning upgrades to VCF 9.1 or ESX 9.1, now is the ideal time to review guest operating system inventories, validate compatibility, and develop migration plans for any workloads still dependent on deprecated or unsupported operating systems.
