NetBackup does not work like that. NetBackup indexes the backup catalog by client name.
You firstly need to identify the client name - it must be exactly the same as in the backup policy.
You then choose the date that you want to restore from. Once you have found and selected the files/folders that you want to restore, NBU will find the tape number that was used for the backup and request the tape mount.
So, open the Backup Archive and Restore GUI on the master server.
Click “File” and select “Specify Netbackup Machines”
Server to be used for backups and restores will always be the master server.
Source client for restores is the client on which the backups were performed. You can click on “Edit Client List” to change the client. This list must also contain the client that you will restore to. This name must match the Client name in the Policy.
Destination client for restores is the client that you will restore to. You can click on the drop down to see a list of clients for selection.
Policy type for restores must correspond to the type of backups in the source client Policy.
Click OK.
Select files'/folders to be restored and click on 'Restore' icon.
In the next screen (Restore Marked files), select whether to restore to same or different location.
Select appropriate Restore Options at the bottom of the screen.
Click 'Start Restore'.
PS:
Are you aware that all NBU versions up to 7.6.x reached EOSL a year ago?
