The method I mentioned is very easy to do. It has the advantage of doing a bacup without having to touch your ShPg, even from a remote terminal. While you are logged into your system snd using it normally, you simply execute one command, and full backup will be done within a minute (only the delta of changed/new files are updated/copied).
Sorry, in my last msg I meant fdisk...
Let us say you are running from the SDCardin the sdcard slot. Have your backup SDCard (or usb stick), formatted just as you formatted your orignal sdcard. If it is a sdcard, you need an sdcard/usb adapter so that your backup sdcard can be plugged into the usb slot.
BTW, you can format and do all the initialization of any sdcard or usbstick (right after you buy one or an older used one) right in the usb slot.
You setup to access the backup card in the normal way to access thru linux from the usb port. Now you simply use rsync (which has to be downloaded/installed just like any new utiity, if you do not already have it on your system), and a single command will copy the image of the sdcard over to your new card. You can stop the computer, and then use the backed up card in the sdcard slot and boot from there.
With other methods described in some of the threads here, you can even avoid having to physically change the cards in the slot. You can boot the system from the sdcard slot or the usbslot, and then change the procedure to backup from the usb slot (now booted from there) to the sdcard slot, which becomes the backup now.
I do the switching to the new card (booting from there) every so often; this assures me that the copy made is functional, without having to wait until trouble strikes. I usually have 2 or more backup cards (rotated through), which insures that there as at least one good backup all the time. (Suppose you have damaged you working os card somehow, and then made s backup copy. Now you have two bad cards
It is in this situation that 3rd copy becomes handy!
If you are not familiar with the necessary linux commands to do all the above (rsync has a lot of options too) steps, I can write a detailed Wiki how to at sometime soon. I just got back just now after being away from home for almost a month.