Backup owner check failed — how to fix it

The “backup owner check failed” error is a common issue when backing up to Proxmox Backup Server. This guide explains why it happens and how to fix it.

What causes this error?

Proxmox Backup Server associates each backup with an owner (authentication identity). When a different user or API token tries to access or modify a backup that belongs to another owner, PBS rejects the operation with a “backup owner check failed” error.

This typically happens when:

• You changed your API token or authentication method
• You’re using a different user account than the one that created the original backups
• Your PBS instance was migrated or reconfigured

How to fix it

Option 1: Use the correct authentication

Make sure you’re using the same user or API token that was used to create the original backups. Check your Proxmox VE storage configuration for the correct credentials.

Option 2: Change the backup owner

On your PBS instance (or via Cloud-PBS dashboard), you can change the owner of existing backup groups:

proxmox-backup-manager change-owner <datastore> <backup-group> <new-owner>

For example:

proxmox-backup-manager change-owner store1 vm/100 user@pbs!newtokenid

Option 3: Use the root@pam account

The root@pam user can access all backups regardless of ownership. However, for Cloud-PBS, we recommend using dedicated API tokens for better security and traceability.

Prevention

• Use API tokens instead of user accounts for automated backups
• Document which token is used for which backup job
• When migrating, update ownership before switching credentials

Need help?

If you’re using Cloud-PBS and need assistance, contact our support team. We can help you resolve ownership issues on your managed instance.