零  配置环境

centos  

一 遇到的问题

问题一: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again

http://mirrors.aliyun.com/centos/6/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
http://mirrors.aliyuncs.com/centos/6/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 7 - "couldn't connect to host"
Trying other mirror.
http://mirrors.cloud.aliyuncs.com/centos/6/os/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: base. Please verify its path and try again

解决方法：

cd /etc/yum.repos.d vi CentOS-Base.repo :%s/$releasever/7/g #将文件中$releasever全部改成7 yum clean all && yum makecache # 清除和缓存

其中$releasever 是获取你centos的版本号的，例如我的centos的版本号为6.7，获取到的为6，但是已经找不到了，所以直接全局改成7即可。

问题二：提示No more mirrors to try

Error Downloading Packages: binutils-2.27-44.base.el7.x86_64: failure: Packages/binutils-2.27-44.base.el7.x86_64.rpm from base: [Errno 256] No more mirrors to try.

解决方法：重新下载

问题三：Public key for glibc-common-2.17-317.el7.x86_64.rpm is not installed

解决方法：

1 导入GPG keys:

#rpm -- import /etc/pki/rpm-gpg/PRM-GPG-KEY -*

2 修改yum源文件，跳过gpg check(不推荐)

把repo文件设置为gpgcheck =0

使用yum install时加上参数 -no gpgcheck

3 下载最新签名（推荐）

cd /etc/pki/rpm-gpg
wget http://mirrors.163.com/centos/RPM-KEY-CentOS-6
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

问题四：ERROR with rpm_check_debug vs depsolve

ERROR with rpm_check_debug vs depsolve:

/sbin/new-kernel-pkg is needed by (installed) kernel-2.6.32-431.el6.x86_64

/sbin/new-kernel-pkg is needed by (installed) kernel-2.6.32-431.el6.x86_64

You could try running: rpm -Va --nofiles --nodigest

Your transaction was saved, rerun it with: yum load-transaction /tmp/yum_save_tx-2020-12-24-08-20xUyYyL.yumtx

 解决方法：待补充

二 下载新的 CentOS-Base.repo 到 /etc/yum.repos.d/

 Centos-6

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-6.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-6.repo

Centos-7

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

Centos-8

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-8.repo
curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-8.repo

sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

三  yum源的常用操作命令

1 清理缓存：yum clean all

2 生成新缓存：yum makecache

3 执行yum更新：yum update