usb.sh:

mkdir -p /tmp/introot && 
mkdir -p /tmp/extroot && 
mount --bind / /tmp/introot && 
mount /dev/sda1 /tmp/extroot && 
tar -C /tmp/introot -cvf - . | tar -C /tmp/extroot -xf - && 
umount /tmp/introot && 
umount /tmp/extroot && 
echo "success"

nohup sh usb.sh > log_out.txt 2>&1 & 

查看执行日志：

tail -f log_out.txt

/etc/fstab 只读无法修改的解决办法

重新挂载为读写文件系统

 mount -o remount,rw / 

修改/etc/config/fstab文件

删除默认的mount信息

config global
    option anon_swap '0'
    option anon_mount '1'
    option auto_swap '1'
    option auto_mount '1'
    option delay_root '5'
    option check_fs '0'

config mount
    option target '/rom'
    option uuid '1f045de8-469f-4786-9614-85ebdf19b519'
    option enabled '0'

config mount
    option target '/mnt/mmcblk2p3'
    option uuid '7df14b19-6e49-4532-bda7-8901e5388e36'
    option enabled '1'

config mount
    option target '/mnt/mmcblk2p4'
    option uuid 'c48f430a-443e-4992-9424-e575f1e1f159'
    option enabled '1'

config mount
    option target '/'
    option uuid 'e5e198c0-53ee-407a-b2a2-a0fc98d68715'
    option enabled '1'

config mount
    option enabled '1'
    option uuid 'e5e198c0-53ee-407a-b2a2-a0fc98d68715'
    option target '/opt'

config mount
    option enabled '1'
    option uuid 'e5e198c0-53ee-407a-b2a2-a0fc98d68715'
    option target '/overlay'

设置显示从哪里启动的：

echo Booted from internal rom >> /etc/banner

docker根目录设置