On Wed, 22 Feb 2012 17:59:59 +0100 Jes.Sorensen@redhat.com wrote:

From: Jes Sorensen <redacted>

Hi,

I have seen this come up on the list a couple of times, and also had
bugs filed over it, since this used to 'work'. Making the printed
error message a little more explicit should hopefully make it clearer
why this is being rejected.

Thoughts?

While I'm always happy to make the error messages more helpful, I don't think
this one does :-(

The reason for the change was that people seemed to often use "--add" when
what they really wanted was "--re-add".
--add will try --re-add first, but it if that doesn't succeed it would do the
plain add and destroy the metadata.

So I introduced the requirement that if you want to destroy metadata, you
need to do it explicitly (and I know that won't stop people, but hopefully it
will slow them down).

Also, this is not at all specific to raid1 - it applies equally to
raid4/5/6/10.

NeilBrown