"Test" and "Failover" options are greyed out for replicated VM in VMware Cloud Director Availability while Replication in "Healthy" state and not failed

Products

• VMware Cloud Director

Issue/Introduction

• In the VMware Cloud Director Availability (VCDA) user interface, the "Test" and "Failover" options are greyed out and unavailable for a replicated virtual machine.
• This typically occurs when the replication appears to be stuck in a "Synchronizing" state for an unusually long time with no visible progress and no red error messages displayed.
  
  

Environment

VMware Cloud Director Availability 4.7.X

Cause

• This issue usually occurs when the background network transfer (NFC connection) silently times out or a process hangs on the host, causing the VCDA user interface and the backend replication engine to lose synchronization.
• Note: For very large virtual machines (e.g., multiple Terabytes in size), it is expected behavior for the initial synchronization to take a significant amount of time (sometimes up to 2 days). During this expected sync period, the Test and Failover options will remain greyed out.

Resolution

• Log in to the destination VCDA Provider Portal.
• Navigate to Incoming Replications.
• Select the stuck replication from the list in the VCDA UI.
• Click the Sync button at the top of the screen.
• Monitor the progress bar for about 10 minutes to verify if the transferred bytes start moving again, indicating the sync has successfully resumed.
• Wait until the sync completes.
• Once the sync completes, wait for a short period until the "Test" and "Failover" options become available.

Additional Information

If the virtual machine is exceptionally large (TB+ size), allow sufficient time (up to 2 days) for the synchronization to complete before assuming the process is hung.