centos7配置yum源出现的问题

配置yum源时报错：

1.本地源未挂载

[root@host yum.repos.d]# yum makecache
已加载插件：fastestmirror
Determining fastest mirrors
 * base: mirrors.aliyun.com
 * extras: mirrors.aliyun.com
 * updates: mirrors.aliyun.com
file:///mnt/cdrom/repodata/repomd.xml: [Errno 14] curl#37 - "Couldn't open file /mnt/cdrom/repodata/repomd.xml"
正在尝试其它镜像。


 One of the configured repositories failed (CentOS-local),
 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=CentOS7 ...

     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 CentOS7
        or
            subscription-manager repos --disable=CentOS7

     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=CentOS7.skip_if_unavailable=true

failure: repodata/repomd.xml from CentOS7: [Errno 256] No more mirrors to try.
file:///mnt/cdrom/repodata/repomd.xml: [Errno 14] curl#37 - "Couldn't open file /mnt/cdrom/repodata/repomd.xml"

本地源没有挂载
vim /etc/fstab
/dev/sr0 /mnt/cdrom iso9660 defaults 0 0 #加上这句 重启 就可以了
2. 本地源没有从/etc/yum.repo.d/目录下移除

...
Cannot find a valid baseurl for repo: base/7/x86_6

若出现以上错误，检查一下本地源是否移除，/etc/yum.repo.d/目录下只留自己创建的文件，检查配置文件，重新挂载