cd /etc/yum.repos.d/
mkdir backup/
cp fedora.repo backup/
cp fedora-modular.repo backup/
cp fedora-updates.repo backup/
cp fedora-updates-modular.repo backup/
2. 更换中科大源
sed -i -e ‘s|^metalink=|#metalink=|g‘ -e ‘s|^#baseurl=http://download.example/pub/fedora/linux|baseurl=https://mirrors.ust edu.cn/fedora|g‘ /etc/yum.repos.d/fedora.repo /etc/yum.repos.d/fedora-modular.repo /etc/yum.repos.d/fedora-updates.repo /etc/yum.repos.d/fedora-updates-modular.repo
3. 更新本地缓存
dnf makecache
RPM Fusion 为 Fedora/RHEL 提供额外的大量 RPM 软件包的第三方软件源
dnf install https://mirrors.ustc.edu.cn/rpmfusion/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://mirrors.ustc.edu.cn/rpmfusion/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
sed -i -e ‘s|^metalink=|#metalink=|g‘ -e ‘s|^#baseurl=http://download1.rpmfusion.org|baseurl=https://mirrors.ustc.edu.cn/rpmfusion|g‘ /etc/yum.repos.d/rpmfusion-free.repo /etc/yum.repos.d/rpmfusion-free-updates.repo /etc/yum.repos.d/rpmfusion-free-updates-testing.repo /etc/yum.repos.d/rpmfusion-nonfree.repo /etc/yum.repos.d/rpmfusion-nonfree-updates.repo /etc/yum.repos.d/rpmfusion-nonfree-updates-testing.repo
dnf makecache
dnf groupupdate core
dnf groupupdate multimedia --setop="install_weak_deps=False" --exclude=PackageKit-gstreamer-plugin
dnf groupupdate sound-and-video
原文：https://www.cnblogs.com/dissipate/p/15156482.html