HowTO-如何降级
breezy -->hoary
1 设定源
deb http://archive.ubuntu.com/ubuntu hoary main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu breezy main restricted universe multiverse
2 设定 pinning
sudo gedit /etc/apt/preferences
加上如下内容
Package: *
Pin: release a=hoary
Pin-Priority: 1001
Package: *
Pin: release a=breezy
Pin-Priority: 60
3 降级
sudo apt-get update
sudo apt-get dist-upgrade
注：有一定的危险，可能会把你系统搞的一团糟，慎用。
