挂载：mount /dev/sdd /opt/usb
错误信息：
mount: wrong fs type, bad option, bad superblock on /dev/sdd,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
查看：lsblk
U盘应该为sdd1并非sdd
修改挂载命令：mount /dev/sdd1 /opt/usb