The inventory reports show the location of the media. These reports are not generated until the media have been ejected.
If you use the NetBackup Administration Console to display an inventory report, you must select a profile that ejects media. Also, select the most recent session for that profile so the most recent data is reported.
More Information
About the Vault Inventory report
About the Offsite Inventory report
About the All Media Inventory report
About reports for media going offsite
About the Reports for media coming on-site
About the Container Inventory report