Sensitive Virtual Machines become impacted by vMotion stun time.

Products

• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x
• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• Application running inside a Virtual Machine may crash
• The virtual machine will not respond to pings briefly
• Database/Banking Applications crash

Environment

• VMware vSphere ESXi 7.x
• VMware vSphere ESXi 8.x

Cause

• When a virtual machine is migrated a brief stun time and fast suspend resume occur in order to move the running virtual machine from one physical ESXi server to another.
  
  
• Whilst the majority of Guest Operating Systems and Applications are not affected by the stun or suspend resume operations, some highly sensitive applications like Database or Banking applications have been known to encounter crash’s or persistent performance impact due to the stun or suspend resume time they experienced as part of the vMotion.
  
  
• The resiliency of the Guest Operating system and its Applications as to how they handle the stun time fall under the responsibility of the creating Vendors for troubleshooting & tuning.

Resolution

1. Exclude sensitive virtual machines from drs or use affinity rules to pin the affected vm’s to specific ESXi hosts in order to prevent them from being migrating.
2. Contact the Guest OS or Application vendor for fine tuning.

Additional Information

https://techdocs.broadcom.com/us/en/vmware-cis/cloud/vmware-cloud-on-aws/SaaS/operations-guide/managing-sddc-hosts-and-clusters/policies-and-profiles/create-or-delete-a-disable-drs-vmotion-policy.html

https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/6-7/vsphere-resource-management-6-7/using-drs-clusters-to-manage-resources/create-a-vm-host-affinity-rule.html

https://blogs.vmware.com/cloud-foundation/2019/07/09/the-vmotion-process-under-the-hood/

高感度な(センシティブな）仮想マシンが受ける vMotionのスタン時間による影響について(430164)