在ubuntu系统下，使用apt-get下载资源时候，总会出现一些404问题，下载很慢，通过如下方是可以有所改善:
修改 vi /etc/apt/sources.list 文件，修改服务器中转为网易镜像服务器：
deb http://mirrors.163.com/ubuntu/ oneiric main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ oneiric main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ oneiric-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-updates universe main multiverse restricted
这样下载速度会快一点。
不至于每次都 apt-get install -y libvirt-dev --fix-missing 好多次还是下载不了。
