Does anyone know how to repair a boot slot?

Installation Home Assistant OS
1

I run HAOS in a VM in ProxMox and ended up creating a problem during some cluster re-configuration where my HA VM ended up starting up on more than one node. This resulted in Boot Slot A getting corrupted. Boot Slot B is still fine.

I can see that boot slot A is /dev/sda3 and B is /dev/sda5. I thought I would be clever and just copy /dev/sda5 → /dev/sda3 with dd which went fine - however HA still will not start on that slot and “os info” shows A as “status: bad, version: null”.

I have nightly HA backups so I have no concern with being able to spin up a new HA VM and reload my backup - however I am a stubborn nerd and this strikes me as an opportunity to learn something.

Where is the metadata for the “boot slots”, e.g. these disk partitions stored? I started poking around in the GRUB configuration but didn’t see anything obvious. What do I need to do to mark Slot A as good? Is there any reason that my bitwise copy of Slot B to Slot A shouldn’t lead to a working Slot A?

Thanks for any help! Again, I can restore from backup if I need to - but I wouldn’t mind just fixing what I have and learning something in the process.

2

Ok, partially answering my own question. It turns out that the kernel image had been corrupted so I had to restore that as well.

The “Slot A” kernel was in /dev/sda2, “Slot B” kernel in /dev/sda4 - “Slot A” root filesystem in /dev/sda3, “Slot B” in /dev/sda5.

dd if=/dev/sda4 of=/dev/sda2
dd if=/dev/sda5 of=/dev/sda3

HAOS can now boot just in from Slot A - HOWEVER “os info” tells me Slot A “version: null”. I would still like to fix that!

Looking around in /mnt/boot/EFI/BOOT I can see where the EFI boot config is all setup, but I don’t see anything there about status, version, etc - so still not sure where this “boot slot” metadata is being stored…

3

Ok, documenting my own journey here LOL.

Looks like all will be revealed here: https://rauc.io/

4

Can you get backup off disk?
If so wouldnt it be easier to reinstall and restore backup?

Nevermind. Carry on.

5

For anyone who finds this later - I was able to completely fix Slot A by making sure I was booted to Slot B, downloading the 14.2 (current version) “ova” raucb file from github (home-assistant/operating-system releases) and then “rauc install {imagefile}”. Decent documentation is available here: Update system | Home Assistant Developer Docs