A new feature needs a newer virtual hardware level
Something in the current vSphere release requires it, and someone has to confirm the blast radius first.
VMware Cloud Foundation guide
Choose a virtual hardware version without creating upgrade debt.
The newest virtual hardware version is not automatically the right one. Kritical helps infrastructure teams make the compatibility decision around the whole operating path — every host, every recovery target and every backup tool that must keep working — not just the newest number available in vSphere.
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Three situations bring teams to this guide.
Compatibility questions rarely arrive on their own.
A migration or refresh is changing the host fleet
New hosts run a newer ESXi build than the oldest node in the cluster, and the gap has to be reconciled.
A recovery test just failed for an undiagnosed reason
The virtual machine restored, but wouldn't power on where it was supposed to.
The newest version is not automatically the right version.
Choose compatibility around every place the virtual machine may need to run: the oldest host in the cluster, recovery infrastructure, backup and replication tooling, test environments and any planned migration target. An upgrade that works on one host can still remove a recovery option the business depends on.
Host compatibility
Confirm the ESX or ESXi releases that may power on, move or recover the virtual machine. Mixed-version clusters and recovery sites make the oldest required platform part of the decision.
Guest support
Check the guest operating system against the current VMware compatibility guidance instead of assuming a newer guest requires the newest virtual hardware.
Protection and recovery
Include backup, replication, restore, disaster recovery and isolated test workflows before changing compatibility.
What you get: a decision that covers the whole platform layer.
The virtual hardware version defines the devices and platform capabilities exposed to the guest. It's separate from the guest operating system, VMware Tools and the application itself — treat those as related lifecycle decisions, not one upgrade button.
Virtual devices and limits
A compatibility level can affect available virtual devices, CPU and memory limits and platform features. We confirm the feature you need before changing it.
VMware Tools
Tools and virtual hardware have different release and support considerations. Updating one does not automatically require updating the other.
Application behaviour
The platform change still needs an application-aware check. A successful power-on is not the same as a successful business service.
Use the current matrix, then test the path you depend on.
Broadcom's compatibility table reviewed in September 2026 maps ESX 9.0 to virtual hardware version 22. VMware Cloud Foundation and vSphere have continued to move, including vSphere 9.1, so we verify the current matrix and product documentation at the time of change rather than copying a version number from an old build guide.
Use the current matrix, then test the path you depend on.
- Broadcom virtual hardware version tableCheck the current mapping between virtual hardware versions, vSphere releases and compatible products. (opens in a new tab)
- What's new with vSphere 9.1Review VMware's current platform release overview before planning a VCF or vSphere lifecycle change. (opens in a new tab)
Why Kritical for this decision.
Inventory the current compatibility level, host and cluster versions, guest support, snapshots, backup state and recovery targets. We agree the validation workload and rollback approach before changing a production virtual machine, and group machines by dependency and risk instead of applying one policy everywhere.
- Before Record the present state, confirm a usable recovery path and identify the platform feature or support need driving the change.
- During Use the supported vCenter workflow, preserve change evidence and stop if the expected compatibility or guest behaviour differs.
- After Validate the application, monitoring, backup and recovery path.
What happens next.
Bring the current vCenter and host versions, the affected workloads and the change you're considering. We'll help establish the safest useful next step, priced in writing.
First call
We confirm the scope of the compatibility question and whether it needs a full VMware Cloud Foundation assessment or a bounded change.
Get a quote
Send the systems and constraints involved and we quote the work.
Questions before you enquire
Should every VM use the newest hardware version?
No. Use the newest level that delivers a required benefit while remaining compatible with the hosts, recovery platforms and operational tools the VM must use.
Does a newer Windows Server guest require the newest VM hardware?
Not automatically. Guest support and VM hardware compatibility are separate questions. We check the current VMware compatibility guidance for the specific guest and platform combination.
Can Kritical review an estate before a VCF or vSphere upgrade?
Yes. We can scope an assessment across host versions, clusters, virtual machine compatibility, guest support, backup and recovery dependencies, then turn the findings into an upgrade or migration plan.
What's the actual risk of getting this wrong?
Usually a virtual machine that can no longer be recovered on the host or backup platform you assumed would still support it. That's why the assessment covers recovery infrastructure.
Can this be batched across a large estate?
Yes. We group machines by dependency and risk rather than applying one blanket policy, so higher-risk systems get more scrutiny than low-risk ones.
Related services
VMware Cloud Foundation
Kritical plans and delivers VMware Cloud Foundation work around the workloads, infrastructure and operating responsibilities that depend on it.
Performance
Kritical investigates difficult performance problems: the slow application, the intermittent stall, or the storage array that looks fine on the dashboard while the business waits.
Windows & Microsoft
Kritical works on Windows infrastructure and the services business applications depend on, including Active Directory, hybrid identity and platform migration.
Backup & recovery
Kritical assesses backup and disaster-recovery arrangements against the systems your organisation needs to restore.
Resources
Use these practical guides to prepare for a renewal, a business-system change or a secure AI project.
Let’s define the next step.
Tell us what you want to achieve, what you have today and when it matters.