Mounting an ISO from content library fails with error " The mount operation could not be finished, as the selected ISO file is currently being Synced. Wait for the Sync operation to finish, and then try to mount the ISO file again."

Products

• VMware vCenter Server

Issue/Introduction

• Mounting an ISO to a VM from content library fails with error :
  
  
  
  
• Also we could see below task "Setting Library Item Tag" being stuck at 0% :
  
  

Environment

VMware vCenter  8.0.x

Cause

This issue is caused by stale or hung import sessions within the vmware-content-library service. These stale sessions occupy the available transfer threads, preventing new tasks from initializing.

Resolution

Follow the below steps to resolve the issue  :

1) Restart the Content Library Service. Log in to the vCenter Server Appliance (VCSA) via SSH as root and run the following command to clear stale sessions:
    service-control --restart vmware-content-library 

2) If the issue persists, you may need to manually clear stalled activities from the vCenter Database (VCDB). Take a Snapshot / backup before implementing in production :    

• Stop the service:
  service-control --stop vmware-content-library
  
  
• Log in to VCDB: 
  /opt/vmware/vpostgres/current/bin/psql -d VCDB -U postgres
  
  
• Run deletion commands:
  delete from cl_simple_activity;
delete from cl_vcenter_task where state ='queued';
  
  
• Start the service: 
  service-control --start vmware-content-library

• Now try mounting the ISO to the Virtual Machine.

Additional Information

After implementing the steps mentioned above, the entries for the "Setting Library Item Tag" task were cleared. We have then successfully mounted an ISO to a VM from the content library.