Logical order to use backup image and sd card size

[najtram]

I know this is more a Raspberry question, but I want to post it on this forum because you understand my wish to keep the current installation and collected data.

My question: How big is a IMG Win32image backup of a 16GB SDCard containing a restored 8GB image with Win32image, without expansion?

Some explaination:
It looks like my SD card is end-of life. So I want to replace it with a new one. I'm using Domoticz for 2 years now, but now I'm stucked with the situation that the new card I bought is smaller than my img. (8GB is not 8GB).

So I want to buy a extra, new, 16GB image to solve this issue. With win32image I will be able to put back the 8GB img to the 16GB. From this new 16GB SD card I want to make backup's with win32image. How big wil this last backup be? (so without any expansion). If this new IMG is 16GB I can expect the same issue after two years ending up to buy a 32GB, 64GB etc.

[freijn]

I believe it will be 16 Gb !

However you can zip the image later on and shrink it again.

[HansieNL]

You can use the option Read Only Allocated Partitions (Gealloceerde Partities Alleen Lezen).
Option to read only to the end of the defined partition(s). Ex: Write a 2G image to a 32G device, reading it to a new file will only read to the end of the defined partition (2G).

[freijn]

Hi Hans

Where can you set this as I do not see it

THanks

Frank

[HansieNL]

Are we talking about the same program?
https://sourceforge.net/projects/win32diskimager/
I pack the created image with WinRAR to zip and then I can later write image back with Etcher without unpacking first.

[Andyf66]

I use raspibackup running via cron job on my Pi. It will shrink the image down to minimum size and can expand it again on restore to fit whichever size device.

https://www.linux-tips-and-tricks.de/en/backup

Originally I was writing backups to a second usb stick, but now I save them remotely on my NAS via an NFS mount.

[najtram]

You can use the option Read Only Allocated Partitions (Gealloceerde Partities Alleen Lezen).

This looks exactly as the option I want. I didn't had this option because I used an older version of W32DI. It is new sinds last years version 1.0!

Thanks HansieNL! This also answers question of Freijn...

[heggink]

why not just insert the new SD as well and dd from old to new?

[najtram]

why not just insert the new SD as well and dd from old to new?

- DD on MacBook is annoying slow!
- I've a MacBook with 1 usb-C slot so I'm stucked with my Windows laptop. So no DD.
- My optimal result is a smaller (8GB) image than the (16GB) SD card, so I can buy each (16GB) SD card to avoid the "8GB is not 8GB" issue.

[najtram]

I pack the created image with WinRAR to zip and then I can later write image back with Etcher without unpacking first.

Is this Etcher program in combination with the smaller ZIP also able to avoid the 8GB is not 8GB issue.

[HansieNL]

Is this Etcher program in combination with the smaller ZIP also able to avoid the 8GB is not 8GB issue.

Yes. I backup my Domoticz server (on a 32GB mSATA SSD) which partitions are total 12GB in size to an image. If I write the zipped image back I still have 12GB. The rest on the disk is unused space.