.
I posted a simple backup program on this forum a while back at:
http://www.knoppix.net/forum/threads...ghlight=backup
I've refined it a bit. Mine now requires only about 77M, about half the space it formerly required.
Not only is this a nice backup, you can use the same procedure to re-establish all your
preferences on the next upgrade of Knoppix, as I just did.

Its use is as follows. More on this in the original reference, if needed.

When you make a new LiveUSB, don't use every last MB for persistence;
leave a little in /mnt-system, say 200MB or so. That is, just devote 200MB LESS to persistence.

After you have modified your new Knoppix LiveUSB somewhat, add 'backup' to your /home/knoppix directory; then, occasionally, as root, exercise 'backup' to put an update.tar.gz file into /mnt-system. Whenever you modify your new system, do another backup to keep current.

If you ever spoil* your knoppix-data.img, delete knoppix-data.img; move update.tar.gz
from the mnt-system into the same directory that knoppix-data.img was in and reboot;
re-establish the persistence file when prompted. Assuming Knoppix is again functioning,
either delete update.tar.gz now or move it back into the /mnt-system directory; don't
leave it in the same directory as knoppix-data.img. Make a new backup soon in any event.

Here's the little program:
Code:
#!/bin/bash
#
# 'backup'
#
# This script captures personal folders, adjustments, choices & tweaks, 
# but does NOT account for program additions or removals 
# relative to the LiveUSB's initial configuration; 
# e.g., changes achieved using Synaptic.
#
# Note: do 'chown root:root backup' & 'chmod +x backup'.
cd /
echo -e 'Tarring data to update.tar in /tmp..\c'                                                     
tar -cf /tmp/update.tar KNOPPIX-DATA/home/ 
tar -rf /tmp/update.tar KNOPPIX-DATA/etc/
tar -rf /tmp/update.tar KNOPPIX-DATA/root/
tar -rf /tmp/update.tar mnt-system/boot/syslinux/syslinux.cfg
echo '..Done.'
#
echo 'Zipping update.tar to update.tar.gz in /tmp.'
echo -e 'Patience; this may take a little time..\c'
cd /tmp #tar -tf update.tar > tar.lst
gzip update.tar; echo '..Done.'
#
echo -e 'Moving update.tar.gz to /mnt-system..\c'
mv update.tar.gz /mnt-system; echo '..Done.'
#
echo 'All done.'
#
exit 0
____________________________

* I consider knoppix-data.img 'spoiled' either when my LiveUSB won't boot, or when the OS
doesn't seem to act as it should. I've spoiled my share.
In my experience this has usually been a result of one of three errors on my part:
1..Changing the plugged status of the USB while it is doing a read or write operation;
2..Bringing in too much additional program content via Synaptic; or
3..Making some OS change as ROOT that didn't turn out right.