1/ a freeware for Windows which can create images of your USB flash drive
USB Image Tool
EDIT: backup file too large (!?)
Gotta find another one…
2/ an opensource deduplicating backup program.
The main goal of Borg is to provide an efficient and secure way to backup data. The data deduplication technique used makes Borg suitable for daily backups since only changes are stored. The authenticated encryption technique makes it suitable for backups to not fully trusted targets.
I’ld like to read your thoughts (noob to Linux and OSMC).