Hello to everybody,
regarding the robustness of the SD card using this option:
on the SD card is stored only boot starter:http://www.berryterminal.com/doku.php/berryboot#berryboot_v20_-_bootloaderuniversal_operating_system_installer
SD card then shut the switch. All traffic data and run only on a USB flash drive. It is quite robust and not prone to mistakes as when it runs only on an SD card.
Sincerely MAPI
Photo: https://pihrt.com/elektronika/248-moje-rapsberry-pi-zavlazovani-zahrady