1、备份源文件

sudo cp /etc/apt/source.list /etc/apt/source.list.backup

2、编辑源列表文件

sudo vim /etc/apt/source.list

3、将原来的列表删除，添加如下内容

deb http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ vivid-backports main restricted universe multiverse

4、运行sudo apt-get update

5、运行sudo apt-get upgrade