Henri Derksen wrote in
>Hello Jan,
>
>JP> 1) make a backup of your 16 GB SDcard, NOT on the raspi,
>
>Why no Pi ?
>
>JP> but on a Linux PC:
>JP> dd if=/dev/X of=cardimage.iso
>
>You forget two important things, i.e. the block size and the Sync !
>So the two commands should be at least:
>
>sudo dd if=/sda of=/dev/sdb bs=1M conv=noerr,sync [RETURN]
>sudo sync                                         [RETURN]
>

Not in my uexperience.
I _do_ use dvdimagecmp to test if the image is the same as the card:
 http://panteltje.com/panteltje/dvd/dvdimagecmp-0.3.tgz

dvdimagecmp -a /dev/sdb -b the_image_i_made

will report errors and progress,
better than 'diff'.


So far never seen an error with
dd if=/dev/whatever of=my_new_perfect_image

:-)

Always use card write to hardidsk, and then hardisk to  cards
I do not delete the hardidsk image either:

panteltje12: /mnt/sda1/encode_ts # l 1/*
-rw-r--r-- 1 root root 8048869376 Dec  8 14:02 1/1.img

'l' (l as in logic, not '1') is bash alias for 'ls -rtl' to save typing.
And if you really want to save typing and use terminals a lot use zsh as shell.
Anyways that is my old 8 GB raspi router image that is now on a 16 GB card.
the '1' refers to the last part of the IP address (fixed), cool way to number
cards.

An other cool thing to store cards, I bought one of these on ebay:
https://ebay.com/itm/252717916459
it arrived yesterday.
You being very precise, make sure you store it in an EMP safe metal box.

dvdimagecmp comes from dvd burning stuff I was (and still am it seems) into:
 http://panteltje.com/panteltje/dvd/index.html

All cards are saved on DVD / bluray whatever, and all are checked,
no sync, no conv=noerr,sync

But feel free to do that :-)


Happy NewYear!

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