CentOS8 更换阿里云 Vault 源并安装 net-tools背景CentOS 8 已于 2021 年底停止维护官方源mirror.centos.org已下线。因此系统内预置的 yum 源地址全部失效直接执行yum install会卡住或报错Could not resolve host: mirrorlist.centos.org解决方案是更换为国内镜像站提供的 CentOS Vault 存档源。操作步骤1. 备份并清空旧仓库配置为避免旧配置残留导致冲突例如出现Repository extras is listed more than once先将所有旧的.repo文件移入备份目录mkdir-p/etc/yum.repos.d/backupmv/etc/yum.repos.d/*.repo /etc/yum.repos.d/backup/2. 下载阿里云 CentOS Vault 源配置curl-o/etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo如果没有curl也可以用wgetwget-O/etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo3. 清理缓存并重建yum clean all yum makecache4. 安装 net-toolsyum-yinstallnet-tools5. 验证ifconfig能正常输出网卡信息即表示安装成功。[rootlocalhost ~]# mkdir -p /etc/yum.repos.d/backup[rootlocalhost ~]# mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/backup/[rootlocalhost ~]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo% Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed1002495100249500107000:00:020:00:02 --:--:--1069[rootlocalhost ~]#[rootlocalhost ~]# yum clean all18files removed[rootlocalhost ~]# yum makecacheCentOS-8.5.2111 - Base - mirrors.aliyun.com355kB/s|4.6MB 00:13 CentOS-8.5.2111 - Extras - mirrors.aliyun.com2.4kB/s|10kB 00:04 CentOS-8.5.2111 - AppStream - mirrors.aliyun.com314kB/s|8.4MB 00:27 Metadata cache created.[rootlocalhost ~]# yum -y install net-toolsLast metadata expiration check:0:02:37 ago on Tue29Sep202612:07:51 PM EDT. Dependencies resolved.Package Architecture Version Repository SizeInstalling: net-tools x86_642.0-0.52.20160912git.el8 base322k Transaction SummaryInstall1Package Total download size:322k Installed size:942k Downloading Packages: net-tools-2.0-0.52.20160912git.el8.x86_64.rpm94kB/s|322kB 00:03 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Total94kB/s|322kB 00:03 Running transaction check Transaction check succeeded. Running transactiontestTransactiontestsucceeded. Running transaction Preparing:1/1 Installing:net-tools-2.0-0.52.20160912git.el8.x86_641/1 Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_641/1 Verifying:net-tools-2.0-0.52.20160912git.el8.x86_641/1 Installed: net-tools-2.0-0.52.20160912git.el8.x86_64 Complete![rootlocalhost ~]#[rootlocalhost ~]# ifconfigens33:flags4163UP,BROADCAST,RUNNING,MULTICASTmtu1500inet192.168.79.149 netmask255.255.255.0 broadcast192.168.79.255 inet6 fe80::86ac:54b6:8933:aada prefixlen64scopeid 0x20linkether 00:0c:29:87:82:f6 txqueuelen1000(Ethernet)RX packets23484bytes29035629(27.6MiB)RX errors0dropped0overruns0frame0TX packets9035bytes826511(807.1KiB)TX errors0dropped0overruns0carrier0collisions0lo:flags73UP,LOOPBACK,RUNNINGmtu65536inet127.0.0.1 netmask255.0.0.0 inet6 ::1 prefixlen128scopeid 0x10hostloop txqueuelen1000(Local Loopback)RX packets0bytes0(0.0B)RX errors0dropped0overruns0frame0TX packets0bytes0(0.0B)TX errors0dropped0overruns0carrier0collisions0常见报错与排查报错信息原因解决方法Repository extras is listed more than once多个.repo文件重复定义了同名仓库清空/etc/yum.repos.d/下所有旧.repo文件只保留新下载的配置Could not resolve host: mirrorlist.centos.org仓库配置仍引用已下线的官方 mirrorlist确认旧配置文件已全部移走重新执行yum clean all yum makecacheCurl error (6): Couldnt resolve host name系统 DNS 或网络不通检查网络连接与/etc/resolv.conf中的 DNS 设置备注CentOS 8 的仓库分为BaseOS、AppStream、Extras三部分阿里云的Centos-vault-8.5.2111.repo已一次性配好无需手动逐个指定。如果后续还需要其他软件包只要源配置正确yum install即可正常使用。建议将本文档保存为centos8-fix-yum.md方便日后重装系统时参考。