vDan

The vSphere Cluster Services (vCLS) are a critical part of maintaining cluster features like vSphere DRS and HA in your VMware environment. But there might be scenarios where you need to disable vCLS on a cluster — for example, for troubleshooting or special configurations. This is where Retreat Mode comes in.

In this post, you’ll learn:

• What Retreat Mode is
• The impact of using it
• How to enable or disable it safely across different vSphere versions

📌 What is vCLS and Retreat Mode?

vCLS deploys lightweight agent VMs in every vSphere cluster to maintain cluster services. Without these VMs, some services like vSphere DRS and HA cannot function properly in vSphere versions prior to 9.0.

Retreat Mode is a way to tell vCenter: “Stop running vCLS VMs on this cluster.” This disables vCLS for that cluster — but at a cost.

👉 Good news:
Starting with vSphere 9.0, you can disable vCLS without losing DRS or HA functionality!

👉 Important for older versions:
In versions before vSphere 9.0, disabling vCLS means DRS will stop working and HA placement will be suboptimal. Also, vSAN cluster health might show as degraded.

⚠️ Risks and Impacts of Retreat Mode

If you enter Retreat Mode on a cluster:

• ✅ vCLS VMs will be removed
• ❌ DRS will stop balancing workloads automatically
• ❌ HA can still restart VMs, but may pick less optimal hosts
• ❌ vSAN cluster health may show “Degraded”

Use Retreat Mode only when absolutely necessary.

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🛠️ How to Enable Retreat Mode

✅ vSphere 7.0 U3o, 8.0 U2, and Later

VMware has made this easy in recent updates:

1. Log in to the vSphere HTML5 Client.
2. Go to Hosts and Clusters.
3. Select your cluster.
4. Click the Configure tab.
5. Under vSphere Cluster Services, click General.
6. Click EDIT VCLS MODE (top right).
7. Select Retreat Mode and click OK.

Done! The vCLS VMs will be cleaned up automatically.

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✅ Older Versions (before 7.0 U3o / 8.0 U2)

This takes a few extra steps:

1️⃣ Log in to vSphere Client.
2️⃣ Go to your cluster and copy its domain ID from the URL. Example:

domain-c1006

⚠️ Only use the domain-c<number>! Using the wrong ID can break vCenter.

3️⃣ In the vCenter Server, go to Configure → Advanced Settings → Edit Settings.

4️⃣ Add a new setting:

Name:  config.vcls.clusters.domain-c<number>.enabled  
Value: False

5️⃣ Click Save.

👉 vCLS VMs will be cleaned up automatically.

6️⃣ To re-enable, set the value back to True.

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✅ Using CLI or API

You can also bulk manage Retreat Mode using the provided Python script:

python retreatModeConfiguration.py -r disable

or

python retreatModeConfiguration.py -r enable

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🔍 How to Identify vCLS VMs

vCLS VMs are named:

vCLS (1), vCLS (2), ...

They are found under a special vCLS folder in VMs and Templates view.

You can also confirm using vSphere Managed Object Browser (MOB):

https://<vCenter_IP>/mob/?moid=vm-1004&doPath=config.managedBy

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✅Sumarry

• vSphere 9.0+: You can disable vCLS safely — DRS and HA won’t be affected.
• Earlier versions: Retreat Mode disables vCLS and disables DRS! Be sure you understand the impact.

Use Retreat Mode responsibly and always monitor your cluster health after making changes.

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👉 For full details, check out the official KB: Disable vCLS on a Cluster via Retreat Mode (KB 316514)

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If you’re planning an upgrade to VMware vSphere 9.0 or just exploring which edition is the right fit for your organization, here’s a clear overview straight from the official vSphere 9.0 Product Line Comparison PDF.

In version 9.0, VMware shifts its focus:

• The traditional vSphere Standard and vSphere Enterprise Plus editions are only available up to version 8 Update 3.
• vSphere 9.0 capabilities are now exclusively packaged as part of VMware vSphere Foundation 9.0 and VMware Cloud Foundation 9.0.

This means new features and innovations, especially around Kubernetes integration, AI services, advanced storage architectures, and modern cloud operations, require the Foundation or Cloud Foundation bundles.

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📊 Full Feature Comparison Table (Extracted and Formatted)

Below is a condensed and formatted table showing a selection of key features across the three product lines:

Feature	vSphere Standard	vSphere Enterprise Plus	vSphere Foundation 9.0
vCenter Edition	Standard	Standard	Standard
vCenter Lifecycle Management Service	✔	✔	✔
Kubernetes Runtime & Supervisor Services	–	–	✔
VM Service, Storage Service, Network Service	–	–	✔
vSphere Lifecycle Manager	✔	✔	✔
Live Patching for ESX	✔	✔	✔
vCenter Server Profiles & Update Planner	✔	✔	✔
Host Profiles & Auto Deploy	–	✔	✔
Green Metrics	✔	✔	✔
Identity Federation	✔	✔	✔
Hardware TPM 2.0 Support	✔	✔	✔
Virtual TPM 2.0	✔	✔	✔
TLS 1.2 / 1.3	✔ / ✔	✔ / ✔	✔ / ✔
Distributed Resource Scheduler (DRS)	–	✔	✔
Instant Clone & Per-VM EVC	–	✔	✔
NVIDIA GRID vGPU	–	✔	✔
Dynamic DirectPath IO	✔	✔	✔
vMotion & Cross-vCenter vMotion	✔	✔	✔
High Availability (HA)	✔	✔	✔
Fault Tolerance	✔ (2 vCPU only)	✔	✔
vSphere Replication & Storage vMotion	✔	✔	✔
vSAN Express Storage Architecture (ESA)	–	–	✔
vSAN Original Storage Architecture (OSA)	–	–	✔
Advanced Data Services (Compression, Encryption)	–	–	✔
External Storage (VMFS, vVols, NFS)	✔	✔	✔
vSphere Distributed Switch	–	✔	✔
Container Networking with Antrea	–	–	✔
VCF Operations: Monitoring, Logs, Compliance	–	–	✔
AI Services & Data Services	–	–	✔
Policy-based Governance & Workload Lifecycle Management	–	✔	✔

(✔ means feature included; – means not included)

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🔑 Summary

• vSphere Standard → Ideal for small deployments with core virtualization needs.

• vSphere Enterprise Plus → Full suite for automation, DRS, and powerful resource scheduling, but limited to version 8.

• vSphere Foundation 9.0 → Next-gen features including Kubernetes, AI services, advanced storage architectures, compliance management, and tight integration with Cloud Foundation.

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• Official VMware vSphere 9.0 Product Line Comparison PDF (2025)

Modern IT teams are increasingly challenged to manage both traditional virtual machines (VMs) and modern Kubernetes workloads side-by-side. VMware Cloud Foundation 9.0 rises to this challenge by tightly integrating vSphere Supervisor, transforming your vSphere clusters into a robust hybrid platform for VMs and Kubernetes.

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In this Hands-On Lab (HOL-2633-01-VCF-L), you’ll get guided, practical experience on how to unify VM and Kubernetes management using vSphere Supervisor, from foundational concepts to deploying real workloads.

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📚 Lab Modules at a Glance

Module	Title	Duration	Level
1	What is the vSphere Supervisor?	15 min	Beginner
2	How does the vSphere Supervisor work?	30 min	Beginner

Let’s break down each module.

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⚙️ Module 1: vSphere Supervisor Concepts and Components

✅ What is vSphere Supervisor?

vSphere Supervisor introduces a declarative Kubernetes control plane natively into your vSphere cluster. This means your cluster can now run:

• VMs via the VM Service
• Kubernetes Pods directly on ESXi hosts (as vSphere Pods)
• Full upstream Kubernetes clusters using vSphere Kubernetes Service (VKS)

This hybrid model enables a consistent cloud-like experience for both traditional and modern workloads.

🔑 Key Components

• vSphere Zone: Logical boundary to provide high availability. Clusters are mapped to Zones for resilience against failures.
• vSphere Namespace: Think of it as a resource pool with policy-based limits (CPU, memory, storage) for workloads. It maps to Kubernetes namespaces but adds vSphere-specific governance.
• Supervisor Networking: Uses either vSphere networking or NSX. Load balancers ensure external access for workloads.
• Supervisor Storage: Utilizes storage policies to manage placement for VMs, Pods, persistent volumes, and container images.

🧩 Extensible Services

vSphere Supervisor comes with base services like:

• VM Service
• Kubernetes Service
• Velero for backup

Additional services (like Grafana, Harbor, DNS, and vDPP) can be installed modularly to enhance the Supervisor’s capabilities.

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🛠️ Module 2: Enabling and Configuring vSphere Supervisor

This module is all about getting your hands dirty — you’ll step through setting up vSphere Supervisor, deploying Namespaces, provisioning VMs and Kubernetes clusters, and expanding functionality with services.

⚡ Key Steps:

🔑 1️⃣ Prerequisites

• Prepare clusters with vSAN or shared storage.
• Define storage policies for control plane, VMs, Pods, and VKS clusters.

🔑 2️⃣ Enable vSphere Supervisor

• Connect to the Management vCenter.
• Create vSphere Zones for high availability.
• Use the wizard to configure networking (NSX or vSphere stack), management network, and workload network.
• Select control plane size and storage policy.

(Note: The lab walks through these steps but does not deploy a live Supervisor due to time constraints.)

🔑 3️⃣ Deploy & Configure a Namespace

• Create a new Namespace and bind it to the Supervisor.
• Assign VM Classes (defining VM sizing options).
• Attach storage policies for workloads.
• Create and associate a Content Library to provide VM templates.

🔑 4️⃣ Deploy Workloads

• Deploy a VM using the VM Service and Consumption Interface.
• Attach persistent storage and a Load Balancer.
• Deploy a Kubernetes cluster (VKS) by specifying node pools and cluster config.
• Validate external access via network service cards.

🔑 5️⃣ Add Services

• Expand functionality by uploading YAMLs to register services like Grafana, Harbor, etc.

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🎓 Summary

✔️ Unified Operations: Manage VMs and Kubernetes side-by-side in the same cluster with consistent policies.
✔️ Self-Service for DevOps: Namespaces, storage, and VM classes empower developers with agility.
✔️ Resilience and Scalability: Zones and Supervisor Services ensure HA and modularity.