备份系统
rsync -aAXv --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found","/etc/fstab"} /* /media/to 恢复系统
rsync -aAXv /media/to/* / --exclude={"/dev/*","/proc/*","/sys/*","/tmp/*","/run/*","/mnt/*","/media/*","/lost+found","/etc/fstab"} 注意事项
如果按照了kvm，需要把kvm卸掉再装。
apt-get remove kvm qemu-kvm && apt-get install kvm qemu-kvm
