VSCSISharedVdMainWorld thread consuming 100% CPU in ESXi 8.0.

Products

• VMware vSphere ESXi 8.0

Issue/Introduction

On VMware ESXi 8.0 hosts, users may observe a specific VMkernel thread, VSCSISharedVdMainWorld, consuming excessive CPU resources.
In some scenarios, CPU utilization on the host may reach and remain at 100%.
This behavior typically occurs in environments where the Clustered VMDK feature is enabled to support workloads such as Windows Server Failover Clustering (WSFC).

Environment

VMware ESXi 8.x

Cause

The issue is triggered by a processing inefficiency within the VSCSISharedVdMainWorld kernel world.
When managing shared storage paths for clustered VMDKs under specific I/O or validation loads, the thread can enter a state of continuous high utilization, impacting overall host performance and potentially leading to cluster validation failures or host instability.

Resolution

This issue is resolved in VMware ESXi 8.0 Update 3h.