Sooner or later, every virtual infrastructure needs a refresh. Whether it’s to patch security holes, fix bugs, or just to get your hands on that shiny new feature VMware added, updates are part of the deal. And here we are: VMware vSphere 8.0 Update 3 is out. I decided to update my lab setup and document the process — from planning to execution.
Introduction
Let’s face it: staying on an outdated hypervisor is tempting, but it catches up eventually. I figured it’s time to upgrade my test environment to vSphere 8.0 Update 3 and see how the process goes. Yes, careful prep is key. You don’t want to wreck your infra or corrupt your VMs.
Why not stay on vSphere 7? Because we’re in 2024 and 8.0 U3 is stable and mature enough to trust. It’s had 3 years to get debugged by the community, and VMware fixed the early quirks.
The Toolkit
Everything here follows VMware’s official upgrade guidance: https://www.vmware.com/products/vsphere/upgrade-center.html
My lab setup mimics a small production cluster. Three Dell PowerEdge R750 servers, all running ESXi 7.0 before the update. Here’s what each host is packing:
- 2 x Intel Xeon Silver 4314
- 256 GB DDR4 RAM
- 2 x 1.92 TB NVMe SSDs (boot + vSAN)
- 4 x 25 GbE NICs
Each node runs several Windows Server 2022 VMs. One of the nodes also hosts the vCenter Server Appliance (VCSA).
Step 1: Check Hardware Compatibility
Start with the basics. Open VMware’s HCL and check if your servers are supported for vSphere 8.0 U3: https://www.vmware.com/resources/compatibility/search.php
If you don’t see your exact model, check the vendor’s docs or reach out to support. Don’t assume it’ll just work. Unsupported hardware = unsupported headaches.
Both my R750s were good to go (they better be, huh).
Step 2: Verify OS and Software Compatibility
Your guest OSes also need to be compatible. Use the VMware Compatibility Guide (software tab): https://www.vmware.com/resources/compatibility/search.php?deviceCategory=software&testConfig=16
All my guests run Windows Server 2022, which is fully supported.
Then check software interoperability, especially your VCSA version: https://www.vmware.com/resources/compatibility/sim/interop_matrix.php
If your current VCSA version isn’t compatible with vSphere 8.0 U3, update VCSA first. Mine was on 7.0 U3, so it had to be upgraded.
Also verify backup solutions, monitoring agents, antivirus software, and any other third-party integrations.
Step 3: Plan the Update Sequence
The order of updates matters. VMware provides a handy KB for this: https://kb.vmware.com/s/article/2147289
For my environment:
- vCenter Server Appliance
- ESXi Hosts
- VMware Tools
- VM Compatibility (virtual hardware)
Start with the control plane (vCenter), then work your way down to the hosts and guest agents.
Step 4: Updating vCenter Server
Use the vCenter Server Installer to deploy a new appliance (Stage 1), then migrate configuration and data from the old one (Stage 2).
Make sure you:
- Have FQDNs and IPs ready
- Use the same SSO domain
- Snapshot the existing VCSA just in case
VMware’s official guide for this is still the best reference: https://docs.vmware.com/en/VMware-vSphere/8.0/com.vmware.vsphere.upgrade.doc/GUID-8C94F03F-2239-47A9-A8D2-A15D728B40E9.html
Once done, shut down the old VCSA but don’t delete it yet.
Step 5: Upgrading ESXi Hosts
You can upgrade ESXi using Lifecycle Manager. In my case, I used the ISO method since it was a clean test setup.
If you go with ISO:
- Mount ISO via iDRAC/iLO
- Choose “Upgrade ESXi, preserve VMFS”
- Confirm settings
Don’t forget to disable HA beforehand and put hosts into maintenance mode.
More details: https://docs.vmware.com/en/VMware-vSphere/8.0/com.vmware.vsphere.upgrade.doc/GUID-4E968653-C2B1-4A9E-AF37-AD3C9034A9E6.html
Step 6: Update VMware Tools and Virtual Hardware
Once all hosts are updated, log into vSphere Client and:
- Update VMware Tools on each VM
- Then upgrade VM Compatibility (virtual hardware version 21 for vSphere 8.0)
Some apps may want a reboot after VMware Tools update, so do it during a maintenance window.
VMware Tools User Guide: https://docs.vmware.com/en/VMware-Tools/index.html
Final Thoughts
Upgrading to vSphere 8.0 Update 3 isn’t difficult, but skipping the prep steps can make it painful. Confirm compatibility, plan your sequence, and take snapshots before touching anything.
VMware documentation has come a long way, so lean on it. With a bit of caution and patience, the whole thing can go surprisingly smooth.
That’s it — lab upgraded, nothing exploded. Now onto the next patch cycle…
