1.更新源的步骤
(1)备份原来的源列表文件
cd /etc/apt/
mv sources.list sources.list.bak
(2)新建源文件,输入源地址
nano sources.list
在nano sources.list输入如下源地址
deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
然后按ctrl+o保存,然后ctrl+x退出
(3)删除旧的源文件
rm /var/lib/apt/lists/*
rm /var/lib/apt/lists/partial/*
(4)最后更新源文件
apt-get update
到此更新源成功Ubuntu14更换源
原文：https://www.cnblogs.com/xiedexiao/p/10086214.html
