Comment 12 for bug 1835091

> If a random person picks up an unused disk of the shelve, they should be able to install onto it, > irrespective that it used to be a partial raid member or not.
>
> Similarly with lvm2 / btrfs / zfs.

We're not in disagreement. We're figuring out best communicate between curtin block-discover and subiquity.

The only answer to your request is to *wipe* the underlying partition or device;

> So i did mdadm --manage --stop /dev/md127 to stop the raid and continue with reuse existing partitions....
>
>.... however curtin was helpful enough to assemble md0 back again, even though we didn't ask for that to happen.

Curtin needs to "awaken" any possible block layer so that it can remove/wipe/clean the data so that when you boot up into the target you don't have a surprise md127 that starts recovering. In this case, subiquity doesn't yet know enough from the curtin discover data that it cannot use preserve on the partition that's a raid member.