A backup presents the warning “Backups to this Account detected from another Backup Client” in the backup log.
The backup may show as successful (With warning/s) or as failed.
In most cases, this is a false positive that only appears once before resolving itself. There are a several possible causes for the warning:
- Migration to new client-side hardware
- Reconnecting to an account using the Account Wizard, which recreates the backupset.xml file
- Antivirus updates interfering with the backupset.xml file
- Manual interference with the backupset.xml file
- Having multiple servers connecting to the same account
- A connectivity interruption between the StorageServer and the machine at the start of the backup (when the connection is resumed, the StorageServer then reads the machine as a new device)
- Operating system updates or a network change
If you see this warning repeatedly, try taking the following steps:
1. Check that you have the required antivirus exclusions in place.
2. If there is a possibility that another machine could be connected to the account, change the encryption key from the correct agent (i.e. the one that should be backing up). This will effectively invalidate the settings on the additional agent and prevent it from connecting, which will reveal where the duplication is coming from.