If you’ve ever stared at those mysterious vCLS VMs running in your clusters, wondered what they were doing, and occasionally cursed them during your backup configs or host evacuations — I’ve got great news.
With vSphere 9.0 (and VCF 9.0), VMware is finally letting us kill vCLS for good.
A Quick Recap: What the Heck Was vCLS?
VMware vSphere Clustering Service (vCLS) dropped with vSphere 7.0 Update 1. It spun up tiny agent VMs on each cluster to maintain DRS and HA services, functioning as a distributed control plane.
It was well-intentioned. But in practice? It caused confusion, got in the way of clean cluster views, created extra noise in snapshots and backup jobs, and frankly just annoyed us.
Then Came vSphere 8.0.3: A Hint of Hope
In 8.0.3, VMware began shifting toward a lighter embedded vCLS model, trimming the resource needs and ditching some of the storage footprint. It was a sign of things to come, but the VMs still lingered like that one intern who won’t stop rebooting your lab.
vSphere 9.0: vCLS Is Officially Deprecated
In vSphere 9.0 (and VCF 9.0), vCLS is now deprecated — and you’ll even see a warning about it when checking the cluster service settings:
“VMware vCenter 9.0 deprecates vCLS, and the service will be removed in a future vCenter release.”
That’s not just a warning. It’s an invitation. VMware even recommends switching to Retreat Mode, stating:
“Deactivating vCLS does not impact vSphere DRS or HA services.”
That’s right. No more vCLS VMs. No impact on functionality. No excuses.
What Replaces It?
Behind the scenes, vSphere 9 introduces a distributed key-value store built directly into the ESXi hosts.
This means cluster state is now:
- Self-contained
- Automatically reconciled if vCenter is restored
- No longer dependent on external agent VMs
In simple terms: the cluster remembers who it is. Even if you reboot, restore, or rage-quit.
How to Enable Retreat Mode (and Evict vCLS Forever)
Want to delete those vCLS VMs once and for all?
Option 1: PowerCLI
$cluster = Get-Cluster -Name "YourClusterName"
$cluster.ExtensionData.ConfigurationEx.ClusterSettings.VclsSettings.Mode = "Retreat"
Option 2: vSphere Client
- Go to Cluster Settings
- Navigate to vCLS
- Click Enable Retreat Mode
Boom. Gone. Forever.
Why This Matters
This is more than deleting some VMs. It’s a clear message from Broadcom/VMware that the platform is shifting toward leaner, smarter, self-reliant architecture.
No fluff. No “helper” VMs. Just native services baked into the core — exactly how it should be.
TL;DR
| vSphere Version | vCLS Status | Notes |
|---|---|---|
| 7.0U1 | Introduced | vCLS VMs deployed per cluster |
| 8.0.3 | Embedded | Reduced overhead, still present |
| 9.0 | Deprecated | Can be deleted via Retreat Mode |
Final Thought: Let Them Retreat
If you’re on vSphere 9.0 or planning your upgrade — this is your cue. Flip on Retreat Mode and enjoy cleaner clusters, fewer headaches, and one less thing to explain to junior admins.
Spring cleaning has never felt so satisfying.
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