When Dup Finder performs a scan, it records details of the storage device in an internal table.
It also includes in the path fields, associated with the folders and files, the current device identity e.g. f:\
But, if the device is removable, there is a chance that when the device is reconnected that it receives a different device identity.
On loading an existing database file Dup Finder checks whether the devices referenced in the database are online or not.
If the device is offline:
If the device is online:
This means that you can create a database for a removable device, save the database on that device. Move the device to another computer and the database is still usable.