ESXi enter maintenance mode stuck at 23% due to large Virtual Machines with CPU reservation

Products

• VMware vCenter Server 8.0

Issue/Introduction

• ESXi enter maintenance mode stuck at 23% with message:
  Waiting for all VMs to be powered off or migrated. In a DRS cluster check the Faults page on the DRS tab for troubleshooting. 
• in DRS fault page, below error indicating insufficient CPU resources.
  The host <HOST_MOREF> can not satisfy the requested CPU resources of <REQUESTED_MHZ> MHz. Available CPU resources on the host: <UNRESERVED_MHZ> MHz.

Environment

vCenter Server 8.0

Cause

DRS initiated vmotion failed due to destination host cannot satisfy CPU resource requirements.

Resolution

Remove CPU reservation for the failed VM.

Or

Add additional CPU resources by adding additional ESXi host.