[VMC on AWS] Bulk migration base sync gets stuck at 0% and time out after a very long time

Products

• VMware Cloud on AWS
• VMware Cloud on Dell EMC

Issue/Introduction

This article explains the troubleshooting steps when base sync is stuck at 0%.

Symptoms:
Bulk migration gets stuck at 0% and when checking app.log for the migration ID we could see 0 bytes will be transferred.
The VM shows a warning banner as Unable to connect to the VR server: Network

Cause

This issue occurs in HCX when the IX appliance on Service Mesh is allowed for the management, vSphere replication but on the On-prem ESXi where the IX appliance is running has a separate vmkernel adapter for vSphere replication and separate vmkernel adapter for Management traffic.

 

 

Resolution

To resolve this issue:

• The user has to create a new network profile with a separate IP on the same IX appliance.
• Once the traffic for the Management and vSphere replication on the IX appliance is going through different network profiles the base sync will start and the VM data will start to replicate and there will be no error banner on the VM.

Workaround:
As a workaround, the user can disable the vSphere replication for the ESXi that the IX appliance is residing on On-prem.

 

Additional Information

Impact/Risks:
The impact with this kind of setup is that the VM will contact the VR server to replicate over to the cloud side. The migration will fail with time out and 0 bytes transferred.