Staging a vCenter Server update fails at 0% in the VAMI

Products

• VMware vCenter Server

Issue/Introduction

• After logging in to vCenter Server Appliance Management Interface (VAMI) at https://<FQDN or IP of vCenter>:5480 and going to Update > Available updates, Select an update and click Stage Only, the progress does not go above 0% and the process fails.
• On the vCenter Server in /var/log/vmware/applmgmt/applmgmt.log, you see the following error:
  • Error reading fss override file [Errno 2] No such file or directory: '/etc/vmware/vsphereFeatures/b2b_fss_override.json'

Environment

vCenter 8.x

Cause

The b2b_fss_override.json file is missing, causing the update staging process to fail. 

Resolution

Follow the below steps:

Important: Take a snapshot of the vCenter before making any change. If multiple vCenters are in linked mode (ELM), it is recommended to save offline snapshots. Refer to Snapshot Best practices for vCenter Server Virtual Machines

1. SSH into the vCenter Server Appliance (VCSA)

   • Use an SSH client (like PuTTY or terminal) to connect to your vCenter.

   • Login as root.

2. Create and edit the file:

   • Use vi or any text editor available: vi /etc/vmware/vsphereFeatures/b2b_fss_override.json

3. Add the following content exactly as shown: {"VMWARE_B2B": true} 

   • In vi editor, press i to enter insert mode, paste the content

   • Press Esc, Type :wq! and hit Enter to save and exit.

4. Verify the file content (optional): cat /etc/vmware/vsphereFeatures/b2b_fss_override.json 

   • Output should be: {"VMWARE_B2B": true}

5. Restart the applmgmt service on the vCenter server:
   
   service-control --restart applmgmt

6. The update staging process will now complete successfully.