Error: "Upgrade validation has failed" while updating vCenter from 9.1.0.0 to 9.1.0.0200 version

Products

• VMware vCenter Server

Issue/Introduction

• When attempting to update vCenter, the upgrade validation process fails with the following error: "The most recent file-based backup of the vCenter Server appliance being upgraded is over 72 hours old. This backup is considered outdated to continue with the upgrade."
  
  
• The following log messages are observed in the vCenter under /var/log/vmware/applmgmt/backup.log:
  
  YYYY-MM-DDTHH:MM:SS.###Z ERROR main ####### [vc@#### requestId="########-#######-#########" processName="VCDBBackup" module="VCDB" funcName="BackupVCDB" fileName="VCDB.py" lineNum="####"] Encounter error during backup VCDB.
Traceback (most recent call last):
File "/usr/lib/applmgmt/backup_restore/py/vmware/appliance/backup_restore/components/VCDB.py", line ####, in BackupVCDB
raise Exception('Full backup not allowed during VM snapshot')

Environment

VMware Cloud Foundation (VCF) 9.x

Cause

• This issue occurs due to the presence of a zero-byte file named backupMarker.txt located in the /etc/vmware/ directory on the vCenter Appliance.
• This file acts as a marker, indicating that a virtual machine snapshot operation is in progress. When this file exists, vCenter prevents any full file-based backup operations to avoid conflicts or corruption during concurrent snapshot-based backups.
• The file may remain in place under the following conditions:
  • A previous backup operation was interrupted or failed.
  • The virtual machine migration activities (e.g., vMotion) occur or are performed. 
  • Third-party backup software creates snapshots but does not clean them up properly.

Resolution

1. Log in to the vCenter appliance via SSH using the root credentials.
   
   
2. Navigate to the VMware configuration directory: cd /etc/vmware
   
   
3. Verify the presence of the snapshot marker file: ls -l backupMarker.txt
   
   
4. If the file exists, delete the file by running: rm /etc/vmware/backupMarker.txt
   
   
5. Reattempt the file-based backup using the VAMI UI.
   
   
6. Monitor future backup operations to ensure that backups complete successfully. 
   
   
7. Retry the vCenter update process.

Additional Information

File-Based backup in vCenter VAMI UI fails with "Full backup not allowed during VM snapshot"