Centons7
其大概意思是fastestmirror不能使用，fastestmirror是yum的一个加速插件，具体我也没有仔细了解过，可能是系统不支持或者缺少组件导致的。
处理办法就是禁用这个插件，方法如下：
[root@localhost ~]# vim /etc/yum/pluginconf.d/fastestmirror.conf
[main]
enabled=1 //1修改为0 禁用该插件
verbose=0
always_print_best_host = true
socket_timeout=3
# Relative paths are relative to the cachedir (and so works for users as well
# as root).
hostfilepath=timedhosts.txt
maxhostfileage=10
maxthreads=15
#exclude=.gov, facebook
#include_only=.nl,.de,.uk,.ie
[root@localhost ~]# vim /etc/yum.conf
[main]
cachedir=/var/cache/yum/$basearch/$releasever
keepcache=0
debuglevel=2
logfile=/var/log/yum.log
exactarch=1
obsoletes=1
gpgcheck=1
plugins=1 //1修改为0 禁用该插件
installonly_limit=5
bugtracker_url=http://bugs.centos.org/set_project.php?project_id=23&ref=http://bugs.centos.org/bug_report_page.php?category=yum
distroverpkg=centos-release
源文章参考网址 ： https://www.cnblogs.com/qiushuiwanyue/p/6568996.html