2015-06-28 Existing lock /var/run/yum.pid の際 Existing lock /var/run/yum.pid: another copy is running as pid 14730. Another app is currently holding the yum lock; waiting for it to exit... The other application is: yum のエラーが出た際は、以下のコマンドでyum.pidを削除してしまえば良いみたい。rm -f /var/run/yum.pid