树莓派挂载U盘

su root
fdisk -l

mkdir /mnt/usb_flash

mount /dev/sda4 /mnt/usb_flash/

umount /mnt/usb_flash


nano /etc/fstab
/dev/sda4 /mnt/usb_flash/    auto     defaults,nofail,x-systemd.device-timeout=1,noatime  0   0