On Mon, 2020-05-25 at 15:43 -0700, Samuel Sieb wrote:
> That decision was taken by mdadm without input from me, i.e.
it's the
> default. I see there is an "--assume-clean" option which would possibly
> have skipped that step, though the man page doesn't recommend it unless
> you know what you're doing, which I clearly don't. All the same, saying
> "the partition table *will* be lost or meaningless after creating
> array" is certainly wrong.
It's not wrong. You were in a very special case where you are
recreating the same raid from two drives that were in exactly the same
configuration. In any other case, the partition table would be
overwritten or would be invalid. You probably could have even used the
"--assume-clean" option to avoid the resync.
Certainly it's a special case, but the message is still wrong to state
that something will happen when it won't. As I said, mdadm has detected
the existence of an array, and knows (or can easily discover) what its
parameters are, and therefore know that the new creation will not
change them.
poc