更换ubuntu16.04 apt源

1- 备份原来的更新源

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

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2- 修改更新源

    sudo vim /etc/apt/sources.list

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3- 替换源文件网址,将下列网址粘贴覆盖到sources.list

    # deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates main restricted
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial universe
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates universe
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial multiverse
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-updates multiverse
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security main restricted
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security universe
    deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial-security multiverse

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对了,替换完成之后一定要记得

        sudo apt-get update
        sudo apt-get upgrade

不然会出现unable locate *** 错误