HA Green - Can't restore backup due to duplicate_os_installation, need to wipe eMMC

Installation
1

Hi all,

I'm trying to migrate my HA Green from an external 1TB HDD to a 500GB SanDisk SSD. Since the SSD is smaller, "Move Data Disk" won't work, so I flashed HAOS 17.3 onto the SSD using Balena Etcher and tried to restore my backup during onboarding.

The problem: I get duplicate_os_installation error blocking the backup restore. This is because the internal eMMC still has the old HAOS partition signature on it.

What I've tried:

  • Ignoring the repair — doesn't fix the underlying block
  • SSH'd in via Advanced SSH add-on — but it drops me into the HA CLI, not a host shell
  • Tried dd if=/dev/zero of=/dev/mmcblk0 — Permission denied
  • Tried docker exec -it hassio_supervisor bash then dd — still Permission denied
  • sgdisk and wipefs are not available

My setup:

  • Hardware: HA Green
  • Current boot: External HDD (Seagate, 1TB)
  • Target: SanDisk Extreme 500GB SSD
  • HAOS version: 17.3

Question: How do I wipe/clear the eMMC partition table on the HA Green to resolve the duplicate OS error? Is there a host shell accessible somewhere?

Thanks!

2
  1. Download the ha-green-erase-eMMC.img file from the official Home Assistant Green documentation.
  2. Use Balena Etcher on your PC to flash this image onto a spare microSD card.
  3. Turn off your HA Green, unplug your external SSD, and insert the microSD card into the slot on the Green.
  4. Turn the power back on. The Green will boot from the SD card and automatically execute a script that safely wipes the internal eMMC partition table clean.
  5. Watch the LEDs on the Green. Once the process is finished (usually indicated by a solid green light or a specific blink pattern described in the guide), pull the power plug.
  6. Remove the microSD card, plug your 500GB SanDisk SSD back in, and power the system back up.

The duplicate_os_installation block will be completely gone, and you can restore your backup perfectly!

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