yum更新报错：YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
1、检查网络是否接通 ping www.baidu.com，如果没有ping成功请先检查网络问题
2、检查 /etc/yum.repos.d/CentOS-Base.repo文件问题
如果发现文件中 http://mirror.centos.org/centos/releasever/updates/releasever/updates/releasever/updates/basearch/无法访问
3、解决404问题，把源站点配置改为国内清华大学站点 https://mirrors.tuna.tsinghua.edu.cn/centos-vault 访问
修改yum源站点配置：vim /etc/yum.repos.d/CentOS-Base.repo
对照清华大学镜像站中的目录修改后如下：
[base] name=CentOS-$releasever - Base #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra #baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/ baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/ gpgcheck=1 #gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/RPM-GPG-KEY-CentOS-6 #released updates [updates] name=CentOS-$releasever - Updates #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra #baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/ baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/updates/x86_64/ gpgcheck=1 #gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/RPM-GPG-KEY-CentOS-6 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra #baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/ baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/extras/x86_64/ gpgcheck=1 #gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/RPM-GPG-KEY-CentOS-6 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever - Plus #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra #baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/ baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/centosplus/x86_64/ gpgcheck=1 enabled=0 #gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/RPM-GPG-KEY-CentOS-6 #contrib - packages by Centos Users [contrib] name=CentOS-$releasever - Contrib #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib&infra=$infra #baseurl=http://mirror.centos.org/centos/$releasever/contrib/$basearch/ baseurl=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/contrib/x86_64/ gpgcheck=1 enabled=0 #gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6 gpgkey=https://mirrors.tuna.tsinghua.edu.cn/centos-vault/6.8/os/x86_64/RPM-GPG-KEY-CentOS-6
4、验证 执行
yum -y update
yum -y install wget
了解以下操作：
通过 执行 man yum 查看yum的帮助信息 可以知道
yum makecache 是 将服务器上的软件包信息 现在本地缓存,以提高 搜索 安装软件的速度
yum 主要的一下命令如下:
yum search 软件包 搜索软件包
yum install 软件包 安装软件包
yum remove 软件包
yum update 更新系统