更改Ubuntu 的apt 源为国内镜像

1. 备份原来的source.list

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

2. 替换为新的镜像源

$ sudo rm /etc/apt/source.list

$ sduo vim /etc/apt/source.list

将下面的内容复制道新建的source.list

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

# newer versions of the distribution.

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted

deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted

## Major bug fix updates produced after the final release of the

## distribution.

deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team.

deb http://mirrors.aliyun.com/ubuntu/ bionic universe

deb-src http://mirrors.aliyun.com/ubuntu/ bionic universe

deb http://mirrors.aliyun.com/ubuntu/ bionic-updates universe

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team, and may not be under a free licence. Please satisfy yourself as to

## your rights to use the software. Also, please note that software in

## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team.

deb http://mirrors.aliyun.com/ubuntu/ bionic multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ bionic multiverse

deb http://mirrors.aliyun.com/ubuntu/ bionic-updates multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates multiverse

## N.B. software from this repository may not have been tested as

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.

deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

## Uncomment the following two lines to add software from Canonical's

## 'partner' repository.

## This software is not part of Ubuntu, but is offered by Canonical and the

## respective vendors as a service to Ubuntu users.

# deb http://archive.canonical.com/ubuntu bionic partner

# deb-src http://archive.canonical.com/ubuntu bionic partner

deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted

deb http://mirrors.aliyun.com/ubuntu/ bionic-security universe

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security universe

deb http://mirrors.aliyun.com/ubuntu/ bionic-security multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security multiverse