We upgraded a client to vSphere 8 last March. Everything went according to plan for exactly 47 minutes. Then their custom firewall script — the one written by an engineer who left the company two years ago — stopped vCenter from starting. The client had 300 VMs running on vSphere 7, and now they could not manage any of them.
That panic call taught us something: vSphere 8 upgrades are not just about clicking "next" in the installer. They are about understanding what changed, what breaks, and what you need to prepare before you touch anything.
We have now completed 23 vSphere 8 upgrades across Philippine enterprises. This guide distills everything we have learned — the good, the bad, and the stuff VMware does not put in the release notes.
What Is New in vSphere 8?
Before diving into the upgrade process, here is what vSphere 8 actually brings to the table. Not marketing highlights — real features that matter for production environments.
DPU (Data Processing Unit) support. vSphere 8 can offload networking and storage operations to a DPU — essentially a smart NIC that runs its own ESXi instance. This frees up CPU and memory on your main hosts. In our testing, DPU-offloaded networking showed 15-20% throughput improvement for storage traffic.
Tanzu integrated clusters. In vSphere 7, Tanzu was a separate product you bolted on. In vSphere 8, Tanzu is natively integrated. If you run Kubernetes workloads, this simplifies the stack significantly. No more separate vSphere with Tanzu licensing.
vSphere Configuration Profiles. Replaces host profiles with a simpler, cluster-level configuration management. Instead of applying profiles to individual hosts, you define the desired configuration at the cluster level, and vSphere enforces it. This is genuinely better than host profiles.
Enhanced DRS. The DRS algorithm has been reworked. It now considers VM memory topology (NUMA nodes), storage I/O, and network I/O when making placement decisions. In our experience, this results in 10-15% better VM density on the same hardware.
vSphere Lifecycle Manager improvements. Single-image and baseline upgrades are now more reliable. The biggest improvement is better hardware compatibility checking — vSphere 8 will warn you about incompatible drivers or firmware before the upgrade starts, not after it fails.
Security enhancements. vSphere 8 enforces TPM 2.0 for host attestation by default. If your hosts do not have TPM 2.0 chips, you need to either install them or configure an exception. This is a hard requirement, not optional.
Why Upgrade? The Business Case
The technical features are nice, but here is what actually motivates our clients to upgrade:
1. Support lifecycle. vSphere 7 enters end of general support in April 2025. If you are still on vSphere 7 after that date, you will only get paid extended support — no more security patches for free. For Philippine enterprises handling sensitive data (healthcare, finance, government), running unsupported infrastructure is a regulatory risk.
2. Hardware compatibility. New server hardware (Intel Sapphire Rapids, AMD Genoa) is only supported on vSphere 8. If you are refreshing hardware in the next 18 months, you need vSphere 8.
3. Cost optimization. vSphere 8 DRS improvements mean you can consolidate more VMs per host. We have seen clients reduce their host count by 15-20% after upgrading, saving on power, cooling, and licensing.
4. Security compliance. The TPM 2.0 enforcement and enhanced Secure Boot support help meet compliance requirements for Philippine Data Privacy Act and international standards like ISO 27001.
Our Upgrade Process: Step by Step
Here is our proven process, refined over 23 upgrades. We always upgrade vCenter first, then ESXi hosts one at a time.
Step 1: Pre-Upgrade Assessment (1-2 days)
We run VMware Compatibility Guide checks for every component: server hardware, storage arrays, network cards, HBA cards, third-party drivers, and management tools.
Critical check: VMware Product Interoperability Matrix. This tells you if your current vCenter version can manage vSphere 8 hosts, and what order you need to upgrade components. For vSphere 8, vCenter must be version 8.0 before you can add any 8.0 hosts.
We also run a pre-upgrade health check using VMware Skyline Health (or the built-in vCenter health check). This identifies potential issues: expired certificates, configuration drift, incompatible VIBs (vSphere Installation Bundles), and storage connectivity problems.
Common pre-upgrade findings in Philippine environments: expired vCenter certificates (30% of clients), incompatible third-party VIBs from backup agents (20%), and outdated storage firmware (15%).
Step 2: Backup Everything (1 day)
Before touching anything, we back up:
1. vCenter Server — full configuration backup via vCenter Server Backup (built into vCenter). Store the backup on a different datastore than vCenter.
2. ESXi host configurations — using ESXi Command Line Interface or PowerCLI to export host settings.
3. VM configurations — export VMX files for all critical VMs.
4. Network configurations — document all port groups, VLANs, distributed switch settings.
5. Storage configurations — document datastores, multipathing, storage policies.
Time investment: typically 2-4 hours for a 10-host environment. This is insurance. If the upgrade goes sideways, this backup gets you back to a working state.
Step 3: Upgrade vCenter Server (1 day)
Always upgrade vCenter first. vCenter 7 cannot manage vSphere 8 hosts — you need vCenter 8.
Process:
1. Mount the vCenter 8 ISO on a management workstation.
2. Run the installer. Select "Upgrade" and point it to your existing vCenter 7.
3. The pre-upgrade checker runs automatically. Fix any issues it identifies before proceeding.
4. The upgrade migrates the vCenter database, configuration, and certificates. This takes 45-90 minutes depending on database size.
5. After upgrade, verify: vCenter is running, all hosts are connected, all VMs are visible, DRS/HA settings are intact.
Gotcha we hit: vCenter 8 requires a minimum of 2 vCPUs and 12GB RAM. If your vCenter 7 was deployed with the minimum specs (2 vCPU, 8GB RAM), you need to resize it before upgrading. VMware does not auto-resize the vCenter appliance.
Step 4: Test with One Host (1 day)
Before upgrading all hosts, we upgrade ONE host and run it for 24 hours in production. This catches compatibility issues that the pre-check missed.
Process:
1. Put the host in maintenance mode. Migrate all VMs to other hosts using vMotion.
2. Enter maintenance mode and disconnect from vCenter.
3. Boot from the vSphere 8 ISO (or use Lifecycle Manager).
4. Follow the upgrade wizard. Choose "Upgrade" to preserve existing VMFS datastores and VM configurations.
5. After upgrade, reconnect to vCenter. Verify the host appears in the cluster with vSphere 8 version.
6. Exit maintenance mode. Allow vMotion to rebalance VMs.
7. Monitor for 24 hours: performance metrics, VM stability, storage connectivity.
Common issues with the test host:
Third-party VIBs that are incompatible with vSphere 8. We encountered this with an older version of the Dell OpenManage VIB. The fix: remove the VIB before upgrading, reinstall the compatible version after.
Hardware health sensors not reporting correctly. The IPMI/iLO/iDRAC interface sometimes needs a firmware update to work with vSphere 8's hardware monitoring.
Step 5: Production Upgrade (2-5 days)
Once the test host is validated, we proceed with the remaining hosts. We upgrade one host at a time, in a rolling fashion:
1. Schedule maintenance windows per host (2 hours each).
2. Migrate VMs off the host using vMotion.
3. Enter maintenance mode.
4. Upgrade using the same process as the test host.
5. Reconnect to vCenter, verify, exit maintenance mode.
6. Move to the next host.
For a 10-host cluster, the full production upgrade typically takes 3-4 days. We do not rush. If any host shows issues during upgrade, we stop, diagnose, and fix before continuing.
Pro tip: upgrade your management host last. This is the host where vCenter runs (if using embedded deployment). Upgrading it first risks losing management access during the upgrade.
Step 6: Post-Upgrade Validation (2-3 days)
After all hosts are upgraded, we run a validation checklist:
1. Verify all VMs are running and accessible.
2. Check DRS recommendations — the new algorithm may suggest different placements.
3. Verify HA configuration — failover tests should still work.
4. Test vMotion — live migration between upgraded hosts.
5. Verify storage — all datastores mounted, all LUNs accessible.
6. Verify backup jobs — backup agents may need updates for vSphere 8 compatibility.
7. Check monitoring — vROps, vRLI, or third-party tools may need updates.
8. Verify TPM/Secure Boot — hosts should show TPM 2.0 attestation if equipped.
9. Run a workload stress test — confirm performance meets or exceeds vSphere 7 baseline.
Best Practices for vSphere 8 Upgrade
1. Upgrade vCenter first, always. This is not optional. vSphere 8 hosts require vCenter 8.
2. Test one host for 24 hours before mass upgrade. This catches 80% of compatibility issues.
3. Update firmware before upgrading. Server BIOS, RAID controller, HBA, and NIC firmware should be at the latest version before the vSphere upgrade.
4. Remove incompatible VIBs proactively. Check the VMware Hardware Compatibility List for your server model. Remove any VIBs that are not listed as compatible.
5. Address TPM 2.0 early. If your hosts do not have TPM 2.0 chips, order them now. Lead times in the Philippines can be 4-8 weeks.
6. Plan for the vCenter resource increase. vCenter 8 needs more RAM than v7. Budget for 12-16GB minimum.
7. Keep a rollback plan. If the vCenter upgrade fails, you can restore from backup. If an ESXi host upgrade fails, you can reinstall ESXi 7 from scratch (preserving VMFS datastores). Document the rollback steps before starting.
Common Mistakes in vSphere 8 Upgrades
Mistake 1: Skipping the pre-upgrade check. The VMware pre-upgrade checker exists for a reason. We have seen clients skip it and discover incompatible firmware mid-upgrade. Always run it.
Mistake 2: Upgrading all hosts simultaneously. Some clients try to save time by upgrading multiple hosts at once. This is risky — if something goes wrong, you lose management access to multiple hosts simultaneously.
Mistake 3: Ignoring third-party integrations. Backup agents, monitoring tools, and management plugins may not be compatible with vSphere 8. Check compatibility for every integrated product before upgrading.
Mistake 4: Forgetting about VM hardware versions. vSphere 8 supports newer VM hardware versions (vmx-21). Existing VMs will not auto-upgrade — you need to manually upgrade VM hardware after the host upgrade. Do this selectively, not for all VMs at once.
Mistake 5: Not testing DRS after upgrade. The new DRS algorithm may make different placement decisions. Monitor DRS recommendations for the first week after upgrade and adjust automation levels if needed.
Conclusion: Upgrade Deliberately, Not Quickly
vSphere 8 is worth upgrading to — the performance improvements, security enhancements, and DRS improvements are real. But the upgrade process requires careful planning and execution.
Here is your action plan:
1. Run the VMware pre-upgrade checker on your environment today.
2. Address any compatibility issues it identifies.
3. Update firmware on all hosts.
4. Back up vCenter and all host configurations.
5. Upgrade vCenter first.
6. Test one host for 24 hours.
7. Upgrade remaining hosts one at a time.
8. Validate everything post-upgrade.
The client whose custom firewall script broke during the upgrade? We fixed it in 30 minutes. But the lesson stuck: know your environment before you upgrade. Every environment is different, and the upgrade process must account for that.
Want to go deeper? Explore [VMware alternatives](/en/vmware-alternative), [Run infrastructure services](/en/products/run), or [platform comparison](/en/compare).
FAQ
Q: How long does a vSphere 8 upgrade take?
For a 10-host cluster: 5-7 days total (1-2 days assessment, 1 day backup, 1 day vCenter upgrade, 1 day test host, 2-3 days production upgrade, 1-2 days validation). Larger clusters take proportionally longer.
Q: Can I upgrade directly from vSphere 7 to vSphere 8?
Yes, direct upgrade from vSphere 7.0 U3 or later to vSphere 8 is supported. If you are on an earlier vSphere 7 version, you need to upgrade to 7.0 U3 first. Upgrade from vSphere 6.x to vSphere 8 requires an intermediate step through vSphere 7.
Q: What happens to my VMs during the upgrade?
VMs continue running during the ESXi host upgrade. vMotion migrates them to other hosts, the host upgrades, and then VMs migrate back. If you are using DRS in fully automated mode, this happens automatically. If DRS is in manual mode, you need to trigger vMotion manually.
Q: Do I need new licenses for vSphere 8?
If you have active vSphere subscriptions, vSphere 8 is included. If you have perpetual licenses, you need to purchase upgrade licenses. Contact your VMware reseller for pricing. Broadcom has changed some licensing terms, so verify your specific situation.
Q: What if the upgrade fails?
For vCenter: restore from backup (you did back up, right?). For ESXi hosts: reinstall ESXi 7 from scratch — your VMFS datastores and VMs are preserved because they are on separate disks. This is why we recommend upgrading one host at a time.