repo 설정파일 생성sudo vi /etc/yum.repos.d/centos8.repo 내용 입력[baseos]name=CentOS 8 BaseOSbaseurl=http://vault.centos.org/8.5.2111/BaseOS/x86_64/os/enabled=1gpgcheck=0[appstream]name=CentOS 8 AppStreambaseurl=http://vault.centos.org/8.5.2111/AppStream/x86_64/os/enabled=1gpgcheck=0 캐시 초기화sudo yum clean allsudo yum makecache