Contains one row for each media family. If a media family resides in a mirrored media set, the family has a separate row for each mirror in the media set. This table is stored in the msdb database.
|Column name||Data type||Description|
|media_set_id||int||Unique identification number that identifies the media set of which this family is a member. References backupmediaset(media_set_id)|
|family_sequence_number||tinyint||Position of this media family in the media set.|
|media_family_id||uniqueidentifier||Unique identification number that identifies the media family. Can be NULL.|
|media_count||int||Number of media in the media family. Can be NULL.|
|logical_device_name||nvarchar(128)||Name of this backup device in sys.backup_devices.name. If this is a temporary backup device (as opposed to a permanent backup device that exists in sys.backup_devices), the value of logical_device_name is NULL.|
|physical_device_name||nvarchar(260)||Physical name of the backup device. Can be NULL. This field is shared between backup and restore process. It may contain the original backup destination path or the original restore source path. Depending on whether backup or restore occurred first on a server for a database. Note that consecutive restores from the same backup file will not update the path regardless of it's location at restore time. Because of this, physical_device_name field cannot be used to see the restore path used.|
|device_type||tinyint||Type of backup device:
2 = Disk
5 = Tape
7 = Virtual device
9 = Azure Storage
105 = A permanent backup device.
Can be NULL.
All permanent device names and device numbers can be found in sys.backup_devices.
|physical_block_size||int||Physical block size used to write the media family. Can be NULL.|
|mirror||tinyint||Mirror number (0-3).|
RESTORE VERIFYONLY FROM backup_device WITH LOADHISTORY populates the columns of the backupmediaset table with the appropriate values from the media-set header.
To reduce the number of rows in this table and in other backup and history tables, execute the sp_delete_backuphistory stored procedure.