Recently I switched some servers from Debian to CentOS because of it’s better hardware vendor support. Apart from the smaller software catalog, especially yum downloads were annoyingly slow. At first I blamed yum’s fastestmirror plugin, however after reading the documentation I discovered that the “fastest” mirror is chosen based on the mirror’s latency not throughput. The mirror hosted by TU Wien (gd.tuwien.ac.at) offers the best latency in Vienna but provides only a throughput of about 200KBps.
Luckily, yum allows you to exclude mirrors matching a given pattern. To add such an exclusion, one has to edit the file “/etc/yum/pluginconf.d/fastestmirror.conf“. Add the following line to exclude all mirrors hosted in Austria:
exclude=.at
After updating the local repository (yum update) the download speed increased instantly. Stjepan also had this problem and solved it the same way.