Hello Jan,

JP> PS what you perhaps 'could' do, if all you have is 1 raspi and 1 card
JP> reader, is boot from some other HUGE[1] SDcard.

The HUGE is the problem.
Until now I only buy the capacity I need, nothing more.

JP> Take the original card and put it in the card reader
JP> copy it to file with dd
JP> dd if=/dev/cardreder of=image1.img

That will take a very long time with no 1M blocks ;-(.
And it will go much faster with 2 identical SDcard reader/writers.

Another solution could be to reduce the image by compression,
i.e. on the fly making them, or afterwards.
Some guy told here how to do it on the fly when making the backup.
I can look up how if you want to know how, or read back yourself.

JP> Now you have the backup.

In stead of a HUGE internal SDcard, a USB stick or HDD is a much better
solution.
I do not know the lifetime of a SSD?
But to keep that as long as possible, reduce the amount of writings,
and do not fill it up for more than 50 %.
The you have the less wear and the longest lifetime.

JP> You could then also copy back to some other card,
JP> put new card in cardreader
JP> dd if=image1.img of=/dev/cardreader

Again the 1M block size is missing ;-(.

JP> All as root, use sudo if you have root fear.

I know.
The first thing I do after installing a new Raspbian Linux,
is to change the default is your fault password.
And of course I write that down somewhere save, my skippers also know.
Only after that you can swith on SSH safely, but I never used that.

JP> [1] must have enough space for the OS and apps and the image.

Making backups on the same media you are using for production is never a good
idea, if you have no other places to store also ;-(.
The SDcards from my camera are never overwritten and copied to external HD's.
When coming home after a trip, I often copy the latest photo's to at least the
external USB HDD.
When the sdCards are full, they are all stored as my original unaltered
"negatives". So I have at least 3 copies of my digital photo's;
The original sdCard, 2 external HDD's and mostly also at a USB stick,
especially the nautical ones about locks an ships, I use much.

JP> Having a PC or laptop with large hardisk, could not do a thing without.
JP> Important backups also go to bluray here.

I donot have BlueRay. Store on several external magnetic HDD's is a better way,
especial when you store vital information also outdoor at family or friends.
CD-drives are often killed by heat ;-(.

JP> So FLASH, magnetic, AND optical.

Yes, that's the right way.
But do some ways double and/or external, i.e. at work or family.

JP> AND I have some MDISKs, supposed to last a century.

What's that MDISKs?

JP> Reality rules,

I know.

JP> if there was a simpler way I'd use it.
JP> Greetings

same to you.
Henri.

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