Error " "Unable to create replica placeholder disk" for certain VM replications in VMware Cloud Director Availability

Products

• VMware Cloud Director

Issue/Introduction

• When configuring/reconfiguring replication for certain virtual machine's in VCDA(VMware Cloud Director Availability), it fails with following errors:
  
  Error: “Unable to create replica placeholder disk '[Datastore_Name] C4-#####-#####-####-####-####/VM_Name.vmdk'.”
  Error: “Unable to create replica placeholder disk '[Datastore_Name] C4-#####-#####-####-####-####/VM_Name.vmdk'.”
  
  
• In the /opt/vmware/h4/cloud/log/cloud.log file on the destination Cloud Director Replication Management Appliance, you see entries similar to:
  
  

  WARN - [UI-#####-#####-####-####-####] [task-poller-1] com.vmware.h4.jobengine.ChildJobManager  : Child job failures [Task{id=#####-#####-####-####-####, user='#####-#####-####-####-####@uservcda', workflowInfo=WorkflowInfo{type='start', resourceType='vmReplication', resourceId='C4-#####-#####-####-####-####', isPrivate=false, resourceName='
VM_Name'}, progress=100, state=FAILED, lastUpdated=1752790391658, startTime=1752790350585, endTime=1752790391658, isAlreadyStarted=false, warnings=[], result=null, error=com.vmware.h4.replicator.api.exceptions.FailedToCreateReplicaPlaceholderDiskException: Unable to create replica placeholder disk '[Datastore_Name] C4-#####-#####-####-####-####/VM_Name.vmdk'.}]
ERROR - [UI-#####-#####-####-####-####] [task-poller-1] com.vmware.h4.jobengine.JobExecution     : Task #####-#####-####-####-#### (WorkflowInfo{type='start', resourceType='vappReplication', resourceId='C4VAPP-#####-#####-####-####-####', isPrivate=false, resourceName='null'}) has failed

  com.vmware.h4.replicator.api.exceptions.FailedToCreateReplicaPlaceholderDiskException: Unable to create replica placeholder disk '[Datastore_Name] C4-#####-#####-####-####-####/VM_Name.vmdk'.
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

Environment

VMware Cloud Director Availability

Cause

This issue occurs when the source virtual machine contains hard disks of invalid capacity(i.e. 0 MB) 

Resolution

To resolve this issue, perform either one of the following options depending on the environment:

1. Re-create the VM disk in vCenter with valid disk size. 
2. Remove the invalid disk from the VM in vCenter.

Once the issues related to VM disks are corrected from vCenter, delete and reconfigure VM replication from VCDA