1. Instal to nandflash

a)download ct-lubuntu-server-vga/hdmi.img.gz
b)extract it
  $gzip -d ct-lubuntu-server-vga/hdmi.img.gz
c)flash it to nandflash with livesuit

2. Install to sata drive

After step 1 is done

a)Power on cubietruck
b)Plug in sata drive after system start up
c)create a new partition for your hard drive
d)write rootfs to the 1st sata drive partition
  #dd if=/dev/nandd of=/dev/sda1 bs=1M
  #sync
  #reboot
e)After reboot,
  #resize2fs /dev/sda1
f)done

If booting from sata failed, the system will fall back to nand rootfs automaticaly, which make
the system more safer.