ubuntu apt-get update 失败解决

转载自（http://feifeifather.blog.163.com/blog/static/21342203220140895556458/）

当运行apt-get update后出现如下错误时：
E: Some index files failed to download, they have been ignored, or old ones used instead.

可以将目录下/var/lib/apt/lists/partial/所有的文件清掉，再次运行apt-get update即可！自带源在大陆不好。