I made a mistake the other day during a transfer of the rootfs to usb. (i got impatient and interrupted the proces, dumb ass, i know)
After a reboot the rootfs was RO. I thought that i would have to reflash dietpi to sd but then i opened dietpi-backup, mounted the rootfs, choose the location of the dietpi-backup. Choose restore. Got a cup of cofee and voila...!! Back in business....

(i am really starting to appreciate and trust Dietpi)
Since i got "dietpi-backup 1" as a cronjob (at 03:00 every day) i lost minimal data (edited scripts)
AND it was so easy!! (and all from a remote location..)
Thanks to all who made this possible...!!!
{Note to self... before attempting a rootfs transfer, first shutdown all process you started from cron. Remove non-essential data (10 Gb of jpg's from ip-cam/webcams)
Greetz from the Netherlands