Clone with Rsync
Let's assume you have an old Setup with a lot of Disks and RAID and so on.To make an easy clone of the whole System to a new bigger Harddrive, you could do the following:
On the original machine, mount the external Harddrive (or mount over the Network while booting the new machine from a LIVE CD)
mkdir /mnt/clone mount /dev/sdx1 /mnt/clone cd / rsync -avz --progress --exclude=/proc/* --exclude=/sys/* --exclude=/dev/* --exclude=/mnt/clone/* /* /mnt/clone/
The rsync above will do a sync of the system at / to the Disk at /mnt/clone/.After you did this, chroot to /mnt/clone and write the bootloader.Be sure to check /etc/fstab for RAID entries and unwanted UUIDs.
If you checked all this , the disk should be ready to boot from and you can throw away the old Setup ;-)