LevelOne NVR-0104 - Manual (Page 117)

NVR-0104 User Manual 117
USB Backup
It’s a function that allows users to backup the recording data in its
database file format (not AVI) to the externally connected USB hard
disk.
You can check the “Disk Status” page under “System Options” to see if
the USB disk has been detected by the NVR. If it's available, it will also
be in the USB HDD drop-down menu in the USB backup page.
* It needs a USB disk containing free space larger than 100MB.