yum源更换错误问题记录
网上查询到的部分源过旧，现在已经不存在404，可以将报错信息中的无法访问的地址在浏览器中尝试。如下http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock这个地址就已经不在。
可以网上搜一下最新的镜像源，如http://mirrors.aliyun.com/repo/Centos-7.repo、http://mirrors.163.com/.help/CentOS7-Base-163.repo等，可以手动下载，再将内容覆盖，也可以wget直接下载（但是我的wget也出问题了需要yum安装）
[root@wenzhu ~]# yum makecache
已加载插件：fastestmirror
Determining fastest mirrors
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=extras&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; 未知的错误"One of the configured repositories failed (未知),and yum doesn't have enough cached data to continue. At this point the onlysafe 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 workingupstream. This is most often useful if you are using a newerdistribution release than is supported by the repository (and thepackages for the previous distribution release still work).3. Run the command with the repository temporarily disabledyum --disablerepo=<repoid> ...4. Disable the repository permanently, so yum won't use it by default. Yumwill then just ignore the repository until you permanently enable itagain or use --enablerepo for temporary usage:yum-config-manager --disable <repoid>orsubscription-manager repos --disable=<repoid>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 muchslower). If it is a very temporary problem though, this is often a nicecompromise:yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=trueCannot find a valid baseurl for repo: extras/7/x86_64
[root@wenzhu ~]# vi /etc/yum.repos.d/CentOS-Base.repo
[root@wenzhu ~]# yum clean all
已加载插件：fastestmirror
正在清理软件源： base extras updates
Cleaning up list of fastest mirrors
[root@wenzhu ~]# yum makecache
已加载插件：fastestmirror
Determining fastest mirrors* base: mirrors.aliyun.com* extras: mirrors.aliyun.com* updates: mirrors.aliyun.com
base | 3.6 kB 00:00:00
extras | 2.9 kB 00:00:00
updates | 2.9 kB 00:00:00
(1/10): base/7/x86_64/group_gz | 153 kB 00:00:00
(2/10): extras/7/x86_64/filelists_db | 305 kB 00:00:00
(3/10): extras/7/x86_64/other_db | 154 kB 00:00:00
(4/10): base/7/x86_64/other_db | 2.6 MB 00:00:00
(5/10): updates/7/x86_64/filelists_db | 15 MB 00:00:02
(6/10): updates/7/x86_64/other_db | 1.6 MB 00:00:00
(7/10): updates/7/x86_64/primary_db | 27 MB 00:00:03
extras/7/x86_64/primary_db FAILED
http://mirrors.aliyuncs.com/centos/7/extras/x86_64/repodata/e12dbf10e94bc2b33b1f45e026559bc8685728b139dddae0654d96bc624c5602-primary.sqlite.bz2: [Errno 14] curl#7 - "Failed connect to mirrors.aliyuncs.com:80; Connection refused" ] 7.1 MB/s | 45 MB 00:00:02 ETA
正在尝试其它镜像。
base/7/x86_64/primary_db FAILED
http://mirrors.cloud.aliyuncs.com/centos/7/os/x86_64/repodata/6d0c3a488c282fe537794b5946b01e28c7f44db79097bb06826e1c0c88bad5ef-primary.sqlite.bz2: [Errno 14] curl#7 - "Failed connect to mirrors.cloud.aliyuncs.com:80; Connection refused"] 7.1 MB/s | 45 MB 00:00:02 ETA
正在尝试其它镜像。
base/7/x86_64/filelists_db FAILED
http://mirrors.aliyuncs.com/centos/7/os/x86_64/repodata/d6d94c7d406fe7ad4902a97104b39a0d8299451832a97f31d71653ba982c955b-filelists.sqlite.bz2: [Errno 14] curl#7 - "Failed connect to mirrors.aliyuncs.com:80; Connection refused" ] 7.1 MB/s | 45 MB 00:00:02 ETA
正在尝试其它镜像。
(8/10): extras/7/x86_64/primary_db | 253 kB 00:00:00
(9/10): base/7/x86_64/primary_db | 6.1 MB 00:00:00
(10/10): base/7/x86_64/filelists_db | 7.2 MB 00:00:01
元数据缓存已建立
[root@wenzhu ~]# 
