1,vi /etc/yum.repos.d/CentOS-Base.repo
CentOS-Base.repo 内容如下：
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-8.5.2111 – Base – mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos-vault/8.5.2111/BaseOS/$basearch/os/
http://mirrors.aliyuncs.com/centos-vault/8.5.2111/BaseOS/$basearch/os/
http://mirrors.cloud.aliyuncs.com/centos-vault/8.5.2111/BaseOS/$basearch/os/
gpgcheck=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-Official
#additional packages that may be useful
[extras]
name=CentOS-8.5.2111 – Extras – mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos-vault/8.5.2111/extras/$basearch/os/
http://mirrors.aliyuncs.com/centos-vault/8.5.2111/extras/$basearch/os/
http://mirrors.cloud.aliyuncs.com/centos-vault/8.5.2111/extras/$basearch/os/
gpgcheck=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-Official
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-8.5.2111 – Plus – mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos-vault/8.5.2111/centosplus/$basearch/os/
http://mirrors.aliyuncs.com/centos-vault/8.5.2111/centosplus/$basearch/os/
http://mirrors.cloud.aliyuncs.com/centos-vault/8.5.2111/centosplus/$basearch/os/
gpgcheck=0
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-Official
[PowerTools]
name=CentOS-8.5.2111 – PowerTools – mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos-vault/8.5.2111/PowerTools/$basearch/os/
http://mirrors.aliyuncs.com/centos-vault/8.5.2111/PowerTools/$basearch/os/
http://mirrors.cloud.aliyuncs.com/centos-vault/8.5.2111/PowerTools/$basearch/os/
gpgcheck=0
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-Official
[AppStream]
name=CentOS-8.5.2111 – AppStream – mirrors.aliyun.com
baseurl=http://mirrors.aliyun.com/centos-vault/8.5.2111/AppStream/$basearch/os/
http://mirrors.aliyuncs.com/centos-vault/8.5.2111/AppStream/$basearch/os/
http://mirrors.cloud.aliyuncs.com/centos-vault/8.5.2111/AppStream/$basearch/os/
gpgcheck=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-Official
2,yum clean all && yum makecache
3.yum update