Rainer Weikusat via Dng <dng@???> writes:
> Not very amusing story someone might nevertheless find quite funny:
>
> I used to run RAID1 system with two RAID devices, one for 'system' and
> one for 'data', with half of the array residing on an internal NVME
> device and the other on an USB disk. I recently bought a webcam. When I
> initially plugged that into an USB port, nothing happened. I then tried
> a reboot. This caused the camera to appear (no idea if it also works)
> but additionally, convinced something in the initramfs to remove all the
> partitions on the USB disk from the corresponding RAID devices, thus
> leaving me with two degraded arrays.
>
> I'll now try to figure out how I can get my missing partitions back ...

Simply re-adding the lost partitions to the RAIDs they belonged to via

mdadm --manage /dev/mdX --add /dev/sdaX

turned out ot work. I now again have to fully functioning RAID devices
which get autostarted on boot. Nevertheless, this was an 'unexpected
feature' I could easily have done without.