操作系统是：centos7
问题：
[root@bd21 yum.repos.d]# yum makecache
Loaded plugins: fastestmirror
http://mirrors.163.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno 14] curl#6 - "Could not resolve host: mirrors.163.com; Unknown error"
Trying other mirror.
One of the configured repositories failed (CentOS-7 - Base - 163.com),
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 base
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=base.skip_if_unavailable=true
failure: repodata/repomd.xml from base: [Errno 256] No more mirrors to try.
http://mirrors.163.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno 14] curl#6 - "Could not resolve host: mirrors.163.com; Unknown error"
[root@bd21 yum.repos.d]#
解决：
[root@bd21 yum.repos.d]# vi /etc/resolv.conf
nameserver 8.8.8.8
nameserver 218.85.157.99
search localdomain
~
~
~
"/etc/resolv.conf" 3L, 64C
[root@bd21 yum.repos.d]# yum clean all
[root@bd21 yum.repos.d]# yum makecache
[root@bd21 yum.repos.d]# yum list