I have a hard drive, that's been disconnected to its computer or over a year now for harware connection reasone.
It contains a RAID parttion that use to part of a RAID1 device on that machine.
Now I want to put it back into its machine, so it can once more fuction as part of the RAID it used to be part of.

But I absolutel don't want any of the data on it to be treated as valid, because it is massively out of date.

But it still has a perfectly valid RAID signature indicating it is part of the RAID it used to be ann active part ot, I am terrified that, after I put the drive back into its machine, the automatic RAID assembly on boot will pick it instaed of the current, up-to-date one as the valid version, and thus lose over a year's data.

**What do I have to do to make sure it is *no longer recognised as part of its RAID*

so that I can boot with the up-to-date OS (and not the ancient one) and properly use mdadm to add it safely as a new RAID component?

All the instructions I've found online an in man pages don't tell me how to remove it from a RAID without it already having been assembled into the RAID. amd that is precisely what I want t prevent from happening prematurely.

-- hendrik