Virtual machines fail to start with the error: Insufficient resources

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Virtual machines fail to start
  
• Virtual machines cannot be started from vSphere Client connected to vCenter Server or directly connected to the ESXi host
• You see the following error:

 

Environment

vSphere 7
vSphere 8

Cause

This error presents when an ESXi host lacks the resources to power on a VM, or one of those resources is experiencing an issue that prevents its provisioning.

Resolution

Potential causes:

• Failed to extend swap file from 0 KB to #### KB" when attempting to power on a virtual machine