sudo apt-get install/update报错

ubuntu安装软件或执行软件更新，sudo apt-get install/update报错，报错如下：

E: Failed to fetch http://mirrors.tuna.tsinghua.edu.cn/ubuntu/pool/main/g/glew/libglew-dev_1.13.02_amd64.deb Temporary failure resolving ‘mirrors.tuna.tsinghua.edu.cn’

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

1. 首先考虑是否为网络状态或软件更新源问题，更新软件源到清华镜像源

sudo vim /etc/apt/sources.list

# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-backports main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-security main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-security main restricted universe multiverse

# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-proposed main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ trusty-proposed main restricted universe multiverse

修改镜像源之后要执行更新

sudo apt-get update
sudo apt-get upgrade

2. 如果软件更新源没有问题，那么是DNS配置出现问题，这里用的是阿里云的DNS服务器，执行下列命令

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
#nameserver 127.0.1.1
nameserver 223.5.5.5  
nameserver 223.6.6.6