earth water air and fire

I want to build a 4 node Raspberry Pi 4 cluster. I did choose the 8 GB RAM models. I already have “earth” and “water” up and running on a 1 GBit switch. I’m still waiting for the stackable case and the rest 2 of the Raspberry Pis. As you may have already guessed they will by called “air” and “fire”.
I did run some 3x1 number calculations on the two Raspberry Pis. It was running fast! I did connect a 512 GB harddisk to “earth” to have a place to store data. On the nodes I did install Raspberry Pi OS lite.
I did set SSH and boot to login on. So I can access the nodes by SSH login.
Everything worked nice so far.
I did install my L1VM and l1vmgodata database. After “earth” was running I did a image of the SD card. And flashed it on the SD card for “water”. After that I just had to change the host name and enable SSH login.
Update: I did add “air” and “fire” to the nodes stack. I did run the cluster 3x1-worker program on the 4 nodes. They did calculate in the range from 1 to 21000000.