vSphere Cluster Services (vCLS) enhancements

Hi, Today i want to write about new feature of vCenter 7 Update 3, With vSphere 7.0 Update 3, vSphere admins can configure vCLS virtual machines to run on specific datastores by configuring the vCLS VMs datastore preference per cluster. Admins can also define compute policies to specify how the vSphere Distributed Resource Scheduler (DRS) should place vCLS agent virtual machines (vCLS VMs) and other groups of workload VMs. 

First of all, What is vSphere Cluster Services (vCLS) ?

vSphere Cluster Services (vCLS) is a new feature in vSphere 7.0 Update 1. This feature ensures cluster services such as vSphere DRS and vSphere HA are all available to maintain the resources and health of the workloads running in the clusters independent of the vCenter Server instance availability.

In vSphere 7.0 Update 1, VMware has released a platform/framework to facilitate them to run independently of the vCenter Server instance availability. In this release, vCenter Server is still required for running cluster services such as vSphere DRS, vSphere HA etc.

vCLS is a mandatory feature that is deployed on each vSphere cluster when vCenter Server is upgraded to Update 1 or when a fresh deployment of vSphere 7.0 Update 1. ESXi host can be of any older version that is compatible with vCenter server 7.0 Update 1.

Size of the vCLS VMs

vSphere Cluster Service VMs are very small VMs compared to workload VMs. Each consumes 1 vCPU and 128 MB of memory and about 500 MB of storage. Below table shows the specification of these VMs:

Memory 128 MB
Memory Reservation 100 MB
Swap Size 256 MB
CPU Reservation 100 MHz
Hard Disk 2 GB
Ethernet Adapter 0 (It is a No NIC VM)
VMDK Size -245 MB
Storage Space -480 MB

How can configure this new feature of vCenter:

Login to your vCenter Server.

Click on your Cluster name and select Configure tab and select vSphere Cluster Services –> Datastores

Click ADD

Select one or more DataStores in which you want vCLS VMs to be created.




Finish 🙂