I have two Raspberry Pi boards. One is a (Pi 1) Model B and the other is a Pi 2 Model B.
The Pi 1 Model B is a new one from my friend. I had used the Pi 2 Model B for a long time.
I know the hardware ability better on Pi 2 B and I use it as a web sever. I consider to shift its "root partition" to the other Pi Model B.
Is this possible to make? I had used "gparted" to see it. There is a protection, a key in front of both boot and root partition.
I had cleaned up the root partition
sudo dd if=/dev/zero of=/dev/the_root_partition(i.e. sda2) bs=64
But, it is not workable.
My simple steps from my idea as below.
Step 1. Only burning the Pi 2 B image's root partition to a image by "dd" command
Step 2. Removing the Model B image's root partition.
Step 3. Buring the image which is saved by Step 1 to the Model B image.
Maybe there is a method to backup separately the boot partition and root partition to the computer. Then, using "dd" to recovery to boot partition and root partition to the empty sd card may be a possible way.
Note: My Pi 2 Model B has upgraded to Raspbian Stretch. In addition, both microSD cards are of same brand, with 32 GB of storage.
2018-04-19 ADDED MORE INFORMATION HERE: I use the "fdisk" to delete the rpi1 sd card's root partition and build a ext4 partition for itself. Then, I use "dd" to copy the rpi2 root partition only to the rpi1's sd card's ext4 empty partition. Then, I insert it to rpi1 board and get successfully booted. But, there is "kernel module failed" message when I boot the system. Even though I have root permission, I still get the message.