# Centos 7 无法使用yum命令解决方法

• 前言

One of the configured repositories failed (Unknown),
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. Disable the repository, 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 <repoid>

4. 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=<repoid>.skip_if_unavailable=true

## 设置网卡开机启动

cd /etc/sysconfig/network-scripts #进入网卡配置目录
ls -al #列出所有文件

ONBOOT=no

service network restart #重启网卡

⚠️注意,如果以上方法不能解决

vim /etc/yum.repos.d/CentOS-Base.repo #如果提示未找到vim , 则使用 vi

:wq 保存后使用 reboot 命令重启服务器即可