1.安装系统默认源，不支持在线更新

[fedora]name=Fedora $releasever - $basearchfailovermethod=priority#baseurl=http://download.fedoraproject.org/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=fedora-$releasever&arch=$basearchenabled=1metadata_expire=7dgpgcheck=1gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$basearch[fedora-debuginfo]name=Fedora $releasever - $basearch - Debugfailovermethod=priority#baseurl=http://download.fedoraproject.org/pub/fedora/linux/releases/$releasever/Everything/$basearch/debug/mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=fedora-debug-$releasever&arch=$basearchenabled=0metadata_expire=7dgpgcheck=1gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$basearch[fedora-sourc