I bought a hdd+sd/tf-card-USB-reader to move/backup the photos of my cameras (several sd/tf-cards) to my server/OMV automatically. (->basically the function of 'usb backup')
After deleting the sd-card (by using option '--remove-source-files') the camera starts with the same filename pattern (e. g. PHO00000.JPG, ....).
Therefore, I get in trouble at the next backup/sync . USB-Backup-plugin (based on rsync?!) overwrites the files....
As a workarround, I set up an OMV-cronjob each x minutes like:
mv /source/sd-card /destination/sd-card"$(date +'-%Y-%m-%d_%H.%M.%S')"
In general it works. But I am not happy with that (error-prone, regularly polling the HDD,..)