1.centos8 yum安装时报错无法从AppStream下载 2.作操作前建议做个快照 3.测试网络是否畅通 ping www.baidu.com 4.更新国内Yum源 #本人用的腾讯源 腾云yum源: https://mirrors.tencent.com/help/centos.html 阿里yum源: https://developer.aliyun.com/mirror/centos 5.将原有源重命名或删除 mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentO S-Base.repo.bak 或 rm -rf /etc/yum/repos.d/CentOS-Base.repo 6. wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos8_base.repo 7.清理之前的Yum缓存yum clean all 8.重新生成缓存 yum makecache 不出意外会报错 Failed to download metadata for repo "AppStream" 9.vim /etc/yum.repos.d/CentOS-Base.repo.rpmsave 找到 [AppStream] name=Qcloud centos AppStream - $basearch baseurl=http://mirrors.cloud.tencent.com/centos/$releasever/AppStream/$basearch/os/ enabled=0 gpgcheck=1 gpgkey=http://mirrors.cloud.tencent.com/centos/RPM-GPG-KEY-CentOS-Official 替换掉 /etc/yum.re pos.d/CentOS-AppStream.repo 里的原[AppStrean] 10.运行yum makecache 成功 11.建议做个快照。建议做个快照