报错“[root@83-83-1-105 ~]# sudo yum install -y epel-release 已加载插件：fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com base | 3.6 kB 00:00:00 http://mirrors.ustc.edu.cn/epel/7/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found 正在尝试其它镜像。 To address this issue please refer to the below wiki article https://wiki.centos.org/yum-errors If above article doesn't help to resolve this issue please use https://bugs.centos.org/. One of the configured repositories failed (Extra Packages for Enterprise Linux 7 - x86_64), and yum doesn't have enough cached data to continue. At this point the only safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Run the command with the repository temporarily disabled yum --disablerepo=epel ... 4. Disable the repository permanently, so yum won't use it by default. Yum will then just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable epel or subscription-manager repos --disable=epel 5. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=epel.skip_if_unavailable=true failure: repodata/repomd.xml from epel: [Errno 256] No more mirrors to try. http://mirrors.ustc.edu.cn/epel/7/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found”

解决方法：

步骤一：备份并删除旧的 epel 源

sudo mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.bak 2>/dev/null
sudo mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.bak 2>/dev/null

步骤二：使用【阿里云 EPEL7 镜像】

sudo tee /etc/yum.repos.d/epel.repo > /dev/null <<EOF
[epel]
name=Extra Packages for Enterprise Linux 7 - \$basearch
baseurl=https://mirrors.aliyun.com/epel/7/\$basearch/
enabled=1
gpgcheck=0
EOF

步骤三：清理缓存并重新生成缓存

sudo yum clean all
sudo yum makecache