# # df
# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 14976 14976 0 100% /
dev 73060 4 73056 0% /dev
tmp 73060 56 73004 0% /var
/dev/mtdblock10 4096 796 330019% /paras
/dev/mtdblock6 77824 53880 2394469% /opt
/dev/sdb1 3938272 21044 3917228 1% /var/usb/sdb1
# su
# /dev/sdb1
sh: /dev/sdb1: Permission denied
# /var/usb/sdb1
sh: /var/usb/sdb1: Permission denied
# 我这个提示这个怎么获得权限呢
