http://forums.gentoo.org/viewtopic.php?t=57471 
http://forums.gentoo.org/viewtopic.php?t=75699
Cách 1:
cp -ax / /mntpoint
the -a will keep permissions and modtimes etc and the -x will only copy stuff on the same partiton – /dev/ and /proc won't be copied to the new partiton, make sure you mkdir /mntpoint/dev and mkdir /mntpoint/proc after you finish copying.
Cách 2:
how about: 
1) mkfs hda8 
2) mount hda8 
3)Code:
rsync -a --exclude /mnt/hda8 / /mnt/hda8
4)fix fstab grub.conf etc. 
5)pray 
6)reboot 
7)#!?!     
8)reboot 
9)done