====== Overview ======
=====This is about how to backup for your Ubuntu system=====
          * make a U disk that have the backup system
          * restart shortcut keys-ctrl+alt+delete
          * F12,select menu->select USB FLASH DRIVE I/O(select U disk)
          * mount '/home/' fold
                  * <code>
mount /dev/sda3 /mnt/custom/sysbak
#using $fdisk -l,we would know detailed infos of disks
#using $fdisk /dev/sda<tab> further know this</code>
          * using fsarchiver make the *.bak files
                  * <code>
fsarchiver savefs /mnt/custom/sysbak/rainbow.fsa /dev/sda2/
#fsarchiver would first pack and compress files in /dev/sda2/ into the rainbow.fsa 
	#and then move to the /mnt/custom/sysbak/ dir</code>
          * check and make sure the size corresponding to /dev/sda2/ is correct
                  * <code>
cd /mnt/custom/
ls -lh</code>
          * unmount
                  * <code>
unmount /mnt/custom/
#unmount not allowed to carry out in the current dir</code>
          * reboot and remember that we set ./nat.sh