Ubuntu modifies the mirror source--Aliyuan

1. Execute the following commands in sequence,

2. sudo gedit /etc/apt/sources.list
   

   
   

3. 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

Copy the above code in, comment out the unneeded source

4

apt-get update

5.

apt-get upgrade