花费了两天的时间做Fedora8自带的yum升级，直到今日才有所进展。我获得成功的直接因素是源自格物至志的帖子，在此向他表示深深的感谢。
办法如下：
编辑相关的repo文件，fedora.repo和fedora-updates.repo
＃fedora.repo文件
[fedora]name=Fedora $releasever - $basearchfailovermethod=priority#baseurl=http://download.fedora.RedHat.com/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/baseurl=http://download.fedora.redhat.com/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirrors.usc.edu/pub/linux/distributions/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirrors.cat.pdx.edu/fedora/linux/releases/$releasever/Everything/$basearch/os/http://ftp.iij.ad.jp/pub/linux/fedora/releases/$releasever/Everything/$basearch/os/ftp://ftp.iij.ad.jp/pub/linux/fedora/releases/$releasever/Everything/$basearch/os/http://mirror.aarnet.edu.au/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirror.internode.on.net/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://gulus.usherbrooke.ca/pub/distro/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirror.karneval.cz/pub/linux/fedora/linux/releases/$releasever/Everything/$basearch/os/http://sunsite.mff.cuni.cz/MIRRORS/fedora.redhat.com/linux/releases/$releasever/Everything/$basearch/os/http://ftp-stud.hs-esslingen.de/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://fedora.tu-chemnitz.de/pub/linux/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirror.fraunhofer.de/download.fedora.redhat.com/fedora/linux/releases/$releasever/Everything/$basearch/os/http://ftp.uni-bayreuth.de/linux/fedora/linux/releases/$releasever/Everything/$basearch/os/http://ftp.funet.fi/pub/mirrors/fedora.redhat.com/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/ftp://ftp.free.fr/mirrors/fedora.redhat.com/fedora/linux/releases/$releasever/Everything/$basearch/os/http://limestone.uoregon.edu/ftp/fedora/linux/releases/$releasever/Everything/$basearch/os/http://fedora.mirror.iweb.ca/releases/$releasever/Everything/$basearch/os/ftp://ftp.cse.buffalo.edu/pub/Linux/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirror.cc.vt.edu/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirrors.tummy.com/pub/fedora.redhat.com/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirrors.kernel.org/fedora/releases/$releasever/Everything/$basearch/os/http://www.gtlib.gatech.edu/pub/fedora.redhat/linux/releases/$releasever/Everything/$basearch/os/http://ftp.linux.ncsu.edu/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://ftp.iij.ad.jp/pub/linux/fedora/releases/$releasever/Everything/$basearch/os/ftp://ftp.iij.ad.jp/pub/linux/fedora/releases/$releasever/Everything/$basearch/os/http://ftp.yz.yamagata-u.ac.jp/pub/linux/fedora/linux/releases/$releasever/Everything/$basearch/os/http://ftp.rhnet.is/pub/fedora/linux/releases/$releasever/Everything/$basearch/os/http://mirror.pacific.net.au/linux/fedora/linux/releases/$releasever/Everything/$basearch/os/#mirrorlist=http://mirrors.fedoraproject.org/mirrorlist?repo=fedora-$releasever&arch=$basearchenabled=1gpgcheck=1gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora file:///etc/pki/rpm-gpg/RPM-GPG-KEY