attach USB flash device

[sarwadenj]

I've LG01 gateway runs openWrt system. I want to attach USB flash device for that i followed your article and https://openwrt.org/docs/guide-user/storage/usb-drives-quickstart artical.
Now USB flash device is mounted.

root@dragino-1c0b14:~# df -h
Filesystem Size Used Available Use% Mounted on
rootfs 3.5M 632.0K 2.9M 18% /
/dev/root 11.0M 11.0M 0 100% /rom
tmpfs 29.8M 484.0K 29.4M 2% /tmp
/dev/mtdblock4 3.5M 632.0K 2.9M 18% /overlay
overlayfs:/overlay 3.5M 632.0K 2.9M 18% /
tmpfs 512.0K 0 512.0K 0% /dev
/dev/sda1 7.0G 16.3M 6.6G 0% /mnt/sda1

now i wanted to copy some file to USB flash device. How to do it, which place i've to store it and run .