Adding new hard disk on a clustered virtual machine with multi writer enabled fails with the error "Incompatible device backing specified for device '0'"

Products

• VMware vCenter Server
• VMware vSphere ESXi 7.0
• VMware vSphere ESXi 8.0
• VMware vSphere ESXi

Issue/Introduction

• Unable to add new hard disk to the first node of the clustered VMDKs on VMFS datastores gives the following error,

Error-Incompatible device backing specified for device '0'.

• Reconfiguration of VM failed and resulted in the following error in hostd.log while adding the new hard disk,

• Checked and confirmed that the disk provisioning for the new hard disk was selected as "Thick provision Lazy Zeroed",

Environment

VMware vCenter Server 7.x

VMware vCenter Server 8.x

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Resolution

While adding new hard disk to the first node with clustered VMDKs on VMFS datastores, select the disk provisioning as "Thick Provision with Eager zeroed" which is the supported configuration.

Reference document:  https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/7-0/setup-for-windows-server-failover-clustering/cluster-virtual-machines-across-physical-esxi-hosts/add-hard-disks-to-first-node-for-cluster-across-physical-hosts-with-clustered-vmdks-on-vmfs.html