【Ubuntu】Ubuntu 18.04 LTS 更換國內源——解決終端下載速度慢的問題
最近裝了ubuntu18.04 LTS，下載軟件有點慢，網上搜了下解決方案，大致是兩種：一、把/etc/apt/sources.list文件裏的源更換一下，改成阿里雲或者其它的鏡像的文件；二、更換software&updates裏的select best server。
一、更換/etc/apt/sources.list文件裏的源
1. 備份源列表
Ubuntu配置的默認源並不是國內的服務器，下載更新軟件都比較慢。首先備份源列表文件sources.list：
# 首先備份源列表
sudo cp /etc/apt/sources.list /etc/apt/sources.list_backup
2. 打開sources.list文件修改
選擇合適的源，替換原文件的內容，保存編輯好的文件, 以阿里雲更新服務器爲例（可以分別測試阿里雲、清華、中科大、163源的速度，選擇最快的）：
# 打開sources.list文件
sudo gedit /etc/apt/sources.list
編輯/etc/apt/sources.list文件, 在文件最前面添加阿里雲鏡像源：
# 阿里源
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
3. 刷新列表
sudo apt-get update
sudo apt-get install build-essential
此時下載速度就明顯加快了
4. 其他源
中科大源：
# 中科大源
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
163源：
# 163源
deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
清華源：
# 清華源
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
更換sources.list速度依然還是很慢就請繼續往下看第二種方法。
二、更換software&updates裏的select best server
這種方法不需要改什麼文件，直接在select best server裏自動選擇。
1. 首先按 WIN鍵,搜索 software,找到 software&updates.
2. 然後點進去,在 Download from裏面選擇 other
3. 然後點擊 select best server按鈕,它會找到最快的那個（最好選比較常用的源，如：清華源，阿里源或者163源之類的這樣會比較穩定）,然後點擊 choose server,就選好鏡像啦.
5. 然後在terminal裏面輸入
sudo apt-get update
看看是不是已經加速了呀！