I sent off a master copy of our emmc image to a vendor for duplication. They proceeded to duplicate it out to 100 emmc modules.
They then booted the master and some of the clone to validate them. (This was not pre-planned)
When an image is booted for the first time does it establish its own UUID and name, or does it have to connect to balena to do that?
Is the master still safe to clone or will all the clones try to register with balena as the same device and break things?
Note that the clones didn’t boot ether, but that is most likely because there is a small modification that has to be made to them per Balena’s emmc support.
My tests have confirmed what I expected – but I needed to be sure. When an image is booted for the first time, it establishes its own UUID without the need for an internet connection. It writes the UUID to the config.json file, thus modifying it in a persistent manner (preserved across reboots). Therefore, I should conclude that the master copy was spoiled by being booted, and it is thus no longer “safe to clone”.
Let us know if you have further questions - we’ll be pleased to help.