Swap SD <> eMMC Installs?

[jdcard]

I still don't understand the boot process, and made the mistake of trying to copy just the Debian partition rather than the entire drive. That didn't work.

Here's what worked:

1. Prepare an empty SD card (formatted as ext4, labelled "XFER") to hold the backup copies. (I had a USB card reader that mounted as /dev/sda1)
   
   
2. Use Gparted to shrink the partitions of each OS to just larger than the actual space being used
   
   
3. Use dd to copy the offline partitions to image files on the fresh SD card (named XFER)
   
   Code:

   sudo dd if=/dev/mmcblk2 of=/run/media/jdcard/XFER/pbpDebian.img
sudo dd if=/dev/mmcblk1 of=/run/media/jdcard/XFER/pbpManjaro.img
   
   
   
4. Use dd to copy the Manjaro image to /dev/mmcblk2 (after verifying that's the right device)
   
   Code:

   sudo dd if=/run/media/jdcard/XFER/pbpManjaro.img of=/dev/mmcblk2 status=progress
   
   
   
5. Boot into the newly-restored Manjaro and use dd to copy the Debian image to another SD card
   
   Code:

   sudo dd if=/run/media/jdcard/XFER/Debian.img of=/dev/mmcblk1 status=progress
   
   
   
6. Use Gparted to resize the partitions of both filesystems to use all the space available on the drives
   

Thanks for the help.