当我尝试运行 yum update all 或 Yum search 时，我得到的只是以下错误：
[root@localhost /]# yum 搜索所有已加载的插件：fastestmirror、langpacks C7.0.1406-base | 3.6 kB 00:00:00
C7.0.1406-centosplus | 3.6 kB 2.9 kB 00:00:00
C7.0.1406-额外 | 2.9 kB 00:00:00
C7.0.1406-fasttrack | 2.9 kB 00:00:00
C7.0.1406-更新 | 2.9 kB 00:00:00
C7.1.1503-碱基 | 3.6 kB 00:00:00
C7.1.1503-centosplus | 3.6 kB 3.4 kB 00:00:00
C7.1.1503-附加 | 3.4 kB 00:00:00
C7.1.1503-fasttrack | 3.4 kB 00:00:00
C7.1.1503-更新 | 3.4 KB 00:00:00
http://vault.centos.org/7.2.1511/os/x86_64/repodata/repomd.xml：[Errno 14]curl#7 - “无法连接到 2a00:f10:10b:13::10：网络无法访问”正在尝试其他镜像。 C7.2.1511-基础 | 3.6 kB 00:00:00
C7.2.1511-centosplus | 3.6 kB 3.4 kB 00:00:00
C7.2.1511-附加 | 3.4 kB 00:00:00
C7.2.1511-fasttrack | 3.3 kB 00:00:00
C7.2.1511-更新 | 3.4 kB 00:00:00
C7.3.1611-基础 | 3.6 kB 00:00:00
C7.3.1611-centosplus | 3.6 kB 3.4 kB 00:00:00
C7.3.1611-附加 | 3.4 kB 00:00:00
C7.3.1611-fasttrack | 3.3 kB 00:00:00
C7.3.1611-更新 | 3.4 kB 00:00:00
基础 | 3.6 kB 00:00:00
基本调试信息 | 2.5 kB 00:00:00
基本源 | 2.9 kB 00:00:00
file:///media/CentOS/repodata/repomd.xml: [Errno 14]curl#37 - “无法打开文件/media/CentOS/repodata/repomd.xml”尝试其他镜像。 file:///media/cdrom/repodata/repomd.xml：[Errno 14]curl#37 -“无法打开文件/media/cdrom/repodata/repomd.xml”尝试其他镜像。 file:///media/cdrecorder/repodata/repomd.xml：[Errno 14]curl#37 -“无法打开文件/media/cdrecorder/repodata/repomd.xml”尝试其他镜像。
配置的存储库之一失败（CentOS-7 - Media），并且 yum 没有足够的缓存数据来继续。此时 yum 能做的唯一安全的事情就是失败。有几种方法可以“修复”这个问题：
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=c7-media ...
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 c7-media
or
subscription-manager repos --disable=c7-media
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=c7-media.skip_if_unavailable=true
失败：来自 c7-media 的 repodata/repomd.xml：[Errno 256] 没有更多镜像可供尝试。 file:///media/CentOS/repodata/repomd.xml：[Errno 14]curl#37 -“无法打开文件/media/CentOS/repodata/repomd.xml”file:///media/cdrom/repodata /repomd.xml：[Errno 14]curl#37 -“无法打开文件/media/cdrom/repodata/repomd.xml”file:///media/cdrecorder/repodata/repomd.xml：[Errno 14]curl #37 - “无法打开文件 /media/cdrecorder/repodata/repomd.xml”