yum源 报错：[Errno 14] HTTP Error 404 - Not Found

正在尝试其它镜像。
To address this issue please refer to the below knowledge base article 

https://access.redhat.com/articles/1320623

If above article doesn't help to resolve this issue please create a bug on https://bugs.centos.org/



 One of the configured repositories failed (onlyoffice repo),
 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=onlyoffice ...

     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 onlyoffice
        or
            subscription-manager repos --disable=onlyoffice

     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=onlyoffice.skip_if_unavailable=true

failure: repodata/repomd.xml from onlyoffice: [Errno 256] No more mirrors to try.
http://download.onlyoffice.com/repo/centos/noarch/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found

原因：yum源地址有问题，要么检查yum源，要么直接换新的yum源。

以下为百度搜索到（错误）：yum源文件有问题而不是索引缓存的问题，光清缓存有屁用;所以下边的方式脑洞有点大。要么查看yum源文件，要么换一个正常机器上的yum源文件。

这个报错是yum源有问题导致的，可以使用下面两个命令解决问题：
`yum clean all`  # 清除所有yum命令的索引缓存
`rpm --rebuilddb`	#重建RPM数据库的命令

解决方案一：找到报错：http://download.onlyoffice.com/repo/centos/noarch/ 的yum源文件修复或者删除。
解决方案二：从其他yum正常的机器上copy一份yum源。
验证方式：yum makecache 通过是否能正常生成yum索引缓存来验证，记得先清除掉所有索引缓存yum clean all