解决Centos下yum无法更新

问题：

http://mirrors.cloud.aliyuncs.com/epel/6/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 6 - "Couldn't resolve host 'mirrors.cloud.aliyuncs.com'"
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: epel. Please verify its path and try again

１、cd /etc/yum.repos.d
２、vim epel.repo
　　nabled=1改为enabled=0