为何无法正确在 usb 盘安装 python？

[luofeiyu]

请参见这篇文章

http://www.2cto.com/Article/201311/257641.html
我照做，出现问题
root@OpenWrt:~# opkg --dest usb install python
Installing python (2.7.9-6) to usb...
Downloading http://downloads.openwrt.org/chaos_calmer/15.05.1/ar71xx/generic/packages/packages/python_2.7.9-6_ar71xx.ipk.
Installing python-db (2.7.9-6) to usb...
Downloading http://downloads.openwrt.org/chaos_calmer/15.05.1/ar71xx/generic/packages/packages/python-db_2.7.9-6_ar71xx.ipk. 省略很多 Configuring terminfo.
grep: /usr/lib/opkg/info/terminfo.control: No such file or directory
cat: can't open '/usr/lib/opkg/info/terminfo.list': No such file or directory
Configuring libdb47.
grep: /usr/lib/opkg/info/libdb47.control: No such file or directory
cat: can't open '/usr/lib/opkg/info/libdb47.list': No such file or directory
Configuring python-db. 省略很多

[fcicq]

猜一下, U 盘是不是 fat 文件系统的?