What causes "Replacement device for" entries in the "Devices" list?

FAQs
1

You may see a strange new entry in your “Devices” list - the new device has the same serial number as another, but the new device is active and the other device is offline. The name in the new entry ends with something like “Replacement device for XXXXX”, where “XXXXX” is the device ID of the old device. And the new entry has the same assigned setup as the old one.

What’s going on?

The short answer is, you put a different SD card, configured to self-register, into a device that was already registered in your account. You can fix the issue by deleting the original device and renaming the new one. For more detailed information, read on.

[The following information is from an info-beamer official support account, in response to a question about exactly this situation.]

For the device “replacement” logic to become active, these things need to happen:

  • A device is configured to self-register with the service using a device connect key. This is a small file on the SD card that contains information that allows the info-beamer backend to assign a device to your account automatically instead of requiring you to enter an 8-digit PIN during installation. This will be the case if you have, for example, used a customised image rather than the default one.

  • A device reset itself and reinitialized the SD card with a new device identity. This happens when:

    • you delete the device from your account (device detail page > Manage > Delete)

    • you swap SD cards between devices.

Once these preconditions met, such a device will contact the backend to see how it should be registered. If it provides a device connect key for self-registration the device is added to the account. The backend then also checks if a device with the same Pi serial number already exists within the account. If that’s the case, the newly added device gets the “Replacement device for ” name and is automatically assigned the same setup.

This is meant to help when replacing SD cards: Use device connect key registration, swap out the card of an already existing device and it will self-register and play the same setup as with the old SD card.

Moving SD cards between devices causes them to reinitialize again, because the device identity (stored on the SD card) is bound to the Pi hardware and moving cards changed that.

See also this related FAQ:

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