backups & cloning

[PJ]

I am getting more and more confused with all the info regarding backing
up and cloning or moving systems from disk to disk or computer to computer.
I would like to do 2 things:
1. clone several instances of 7.2 from and existing installation
2. set up a backup script to back up changes either every night or once
a week

There are numerous solutions out there; but they are mostly confusing,
erroneous or non functional.
To start, could someone please explail to the the following, which I
found here:http://forums.freebsd.org/showthread.php?t=185

You can move system from disk to disk on fly with
Code:

$ newfs -U /dev/ad2s1a
$ mount /dev/ad2s1a.... /target
$ cd /target
$ dump -0Lauf - /dev/ad1s1a  | restore -rf -

you can do the same using sudo
Code:

$ sudo echo
$ sudo dump -0Lauf - /dev/ad1s1a  | sudo restore -rf -

This may be clear to someone; it certainly is not to me.
As I understand it, newfs will (re)format the slice.
Ok,  But what is standard out in the above example.  The dump is from
where to where?
Could someone clarify all this for me?
So far, I have been unable to dump the / slice, not even with the -L
option. I am trying to dump the whole system (all the slices)except swap
to a usb (sata2 500gb disk) and then restore to another computer with
7.2 minimal installation.
Slices ad2s1d,e,f and g dump ok to usb. a does not - errors ("should use
-L when dumping live filesystems)
Do you have to newfs each slice before restoring?  But if you are
restoring on a running 7.2 system, don't you have to restore to another
disk than the one the system is on?
I am beginning to think that you have to have a system running and dumpt
to another disk on that system and then remove that disk and install in
another box and boot from that?
Am I getting close?
I know it's a lot to ask, but then, I know you guys are capable...  :-)