How to Remove vSphere Cluster Service VMs Securely

What is vSphere Cluster Services (vCLS)

vSphere Cluster Services (vCLS) is a new feature in vSphere 7.0 Update 1, which ensures cluster services such as vSphere DRS and vSphere HA. VMware says that vCLS uses agent virtual machines (vCLS VMs) to maintain the health of cluster services, even if the vCenter Server is not available. The vCLS VMs are created when you add hosts to clusters. There will be 1 to 3 vCLS VMs running on each vSphere cluster depending on the size of the cluster.

vCLS is also a mandatory feature which is deployed on each vSphere cluster when vCenter Server is upgraded to Update 1 or after a fresh deployment of vSphere 7.0 Update 1. There is no way to disable vCLS on a vSphere cluster and still have vSphere DRS being functional on that cluster. If you try to remove vSphere Cluster Service VMs, you will get a warning, and they will be automatically powered back on anyway as the vCLS monitoring service runs every 30 seconds.

However, it is possible to manually disable vCLS on a vSphere cluster via Retreat Mode, but some of the cluster's services, such as DRS, will be affected. Today, I will introduce how to remove vSphere Cluster Services VMs securely using Retreat Mode.

How to remove vSphere Cluster Service VM Step by Step

You can disable vCLS in VMware on a cluster by following the Retreat Mode steps below, but this will impact some of the cluster services for that cluster.

1. Login to the vSphere Client, and find the cluster domain ID of the cluster we want to put in retreat mode. Select the cluster in the vSphere client and look for the “domain-cXXX” section in the url of your browser.

2.Navigate to vCenter, and select Configure >> Settings >> Advanced Settings section and then on Edit settings button.

3. Add a new entry with name = config.vcls.clusters.domain-c.enabled and value = False. Click Save.

Note: True and False are case-insensitive, so any case of these two values should be accepted.

Now the vSphere Cluster Service VMs are going to be removed from the cluster, and the Cluster Services health will be set to Degraded and DRS will stop working.

4. If this cluster has DRS enabled, then it will not be functional and an additional warning will be displayed in the cluster summary. DRS will be disabled until vCLS is re-enabled on this cluster. To remove Retreat Mode from the cluster, change the value to True in step# 3 above.

You have deleted vCLS VMs by following the Revert Mode steps. As we know, vCLS ensures that if vCenter Server becomes unavailable, cluster services remain available to maintain the resources and health of the workloads that run in the clusters.

To create a better vSphere environment, the vSphere backup solution delivers complete data protection for vCenter-managed and standalone ESXi workloads.

VMware vSphere backup solution you can try (built-in)

In addition to professional backup software, you can actually try some of the built-in features for vSphere backup solutions.

✦ Manually copy VM disk files: A VM is essentially a set of files. The virtual disk files can be direct open by the hypervisor.

✦ Export VM to OVF/OVA: Open Virtualization Format (OVF) is a file format that supports exchange of virtual appliances across products and platforms. You can achieve faster downloads this way, but still need to export VM from ESXi one by one.

✦ Agent-based VM backup: You can perform file-based backup by using Windows Server Backup or Backup and Restore that come with Windows guest operating systems. But it cannot backup the host and guest configurations, and perform file-based backup on multiple VMs one by one can be laborious. The built-in features need to be done manually on a VM-by-VM basis, and are therefore not suitable for centralized management and batch operation situations. So many IT staff prefers to choose a professional VMware Backup software that offers auto and complete VM backups.

AOMEI Cyber Backup is the most reliable way to backup VMs today. You can create independent and complete backups of multiple VMs with simple steps. This software can help you to do the followings easily.

Easy-to-use: backup and restore multiple virtual machines via central console without complicated configuration and reinstallation.
Support Free ESXi: support both paid and free versions of VMware ESXi.
Multiple VM Backup: batch backup large numbers of VMs managed by vCenter Server, or multiple VMs on a standalone ESXi host.
Automatic VMware Backup: Auto backup virtual machines on regular basis to protect VMware workloads continuously.
Restore from Any Point easily: Restore VM from any backup point directly and quickly, eliminating the need to restore a full backup plus each subsequent backup point.
Role-Assignment: allow one administrator to create sub-accounts with limited privilege, effectively reduce administration cost and manual errors.

AOMEI Cyber Backup supports VMware ESXi 6.0 and later versions. Next, I will show you how to batch backup VMs managed by vCenter Server with AOMEI Cyber Backup in 5 simple steps. You can click the following button to download the software.

*You can choose to install this VM backup software on either Windows or Linux system.

5 Steps to perform backup and recovery

1. Bind Devices: Access to AOMEI Cyber Backup web client, navigate to Source Device >> VMware >> + Add VMware vCenter or Standalone ESXi host. And then click … >> Bind Device.

2. Create Backup Task: Navigate to Backup Task >> + Create New Task, and then select VMware ESXi Backup as the Device Type.

3. Set Task Name, Device, Target, Schedule, and Cleanup as need.

• Task Name: you can chance the task name or use the default name with an ordinal.
• Device: batch select large numbers of VMs managed by vCenter Server for centralized backup.
• Target: select to back up to a local path, or to a network path.
• Schedule (optional): perform full, differential or incremental backup, and automate execution according to the frequency you specified.
• Cleanup (optional): automatically delete the old backup copies that exceed the retention period you specified.

4. Run Backup: Click Start Backup and select Add the schedule and start backup now, or Add the schedule only.

Created backup tasks will be listed and monitored separately, for restoring, progress checking and schedule changing.

5. When restoring, you can also restore to new location to create a new VM in the same or another datastore/host directly from the backup, saves the trouble of re-configuring the new VM.

• Select  Restore >> Restore to original or new location to recover a VM from ant selected backup version. It easily makes a clone of a virtual machine in the same or another datastore/host, without reinstalling or configuring a new VM.

Within several clicks, you can simply obtain secure backups of multiple virtual machines and restore entire VM timely, which helps you recover VM in the event of a disaster and protects VM data security.

Summary

The vCLS agent VMs might be created on a datastore where you'll need to do maintenance. Besides vSphere DRS, High Availability (HA) will not perform optimal placement during a host failure. vSphere HA depends on DRS for placement recommendations; as such, it needs the Retreat Mode deactivated.

This article describes the steps to remove vSphere Cluster Service VMs and give you a quick introduction to remove Retreat Mode from the cluster.