Statement about supportability of cloning ESXi boot devices for deployments

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
While cloning an ESXi boot device in order to speed up the deployment of servers has been a practice for some customers, this workflow is not at all supported by VMware. This is because our ESXi’s operating system expects that each server will have a unique System Universally Unique Identifier (UUID). Cloning an ESXi boot device will also replicate that System UUID, which can lead to VMFS corruption if multiple hosts with the same System UUID share the same VMFS volumes, as there are dependencies in the storage stack that uses the System UUID for operations like VMFS journaling and VMFS Heartbeat operations. There are additional dependencies on unique System UUIDs in ESXi 7.0 (Encrypted keys for TPM, etc) as we always expect the System UUID to be unique and not copied.

Environment

VMware vSphere ESXi 7.0.0
VMware vSphere ESXi 7.0.x

Resolution

The only supported solution at this time is to rebuild the ESXi hosts, which will generate a new System UUID. Any datastores that become corrupt as a result of duplicate System UUIDs will need to be reformatted after evacuating the present VMs.

For more information about VMFS corruption that can occur because of duplicate System UUIDs, please see the following KB article: https://knowledge.broadcom.com/external/article?articleNumber=318630