Power on task of VM fails with error "Cannot enable changed block tracking and multi-writer sharing at the same time. Failed to start the virtual machine" but multi-writer sharing is not enabled

Products

• VMware vSphere ESXi

Issue/Introduction

• When trying to power on a VM below error is seen: 

"Cannot enable changed block tracking and multi-writer sharing at the same time. Failed to start the virtual machine. Module Disk power on failed. Cannot open the disk '/vmfs/volumes/####################/Test.vmdk' or one of the snapshot disks it depends on. One of the parameters supplied is invalid"

 

• Multi-writer sharing is not enabled on the VM disks 
• Change Block Tracking (CBT) and SCSI Bus-sharing is enabled on the VM 

 

Environment

vCenter Server 7.0

vCenter Server 8.0 

ESXi 7.0 

ESXi 8.0 

Cause

SCSI Bus-sharing and snapshots are not supported together, so enabling CBT on VMDKs which SCSI is bus-sharing is also not supported 

Resolution

If you have SCSI bus-sharing configured on a VM, ensure that CBT is not enabled on the VMDKs related to this SCSI controller. CBT can be disabled follow below KB steps: 

Enabling or disabling Changed Block Tracking (CBT) on virtual machines

Once CBT is disabled, the VM should power on. 

Additional Information

See below documentation on this: 

Unable to use Snapshots or perform a backup on virtual machines configured with bus-sharing

"Snapshots are not supported on disks connected to controllers configured for bus-sharing configuration."

Snapshot Limitations