Tim Woodall (12023-03-17):
> Yes. It's possible. Took me about 5 minutes to work out the steps. All
> of which are already mentioned upthread.
All of them, except one.
> mdadm --build ${md} --level=raid1 --raid-devices=2 ${d1} missing
Until now, all suggestions with mdadm started with:
mdadm --create /dev/md0 --level=mirror --force --raid-devices=1 \
--metadata=1.0 /dev/local_dev missing
You suggest --build rather than --create, and indeed:
Build Build an array that doesn't have per-device metadata (su‐
perblocks). For these sorts of arrays, mdadm cannot differenti‐
ate between initial creation and subsequent assembly of an ar‐
ray. It also cannot perform any checks that appropriate compo‐
nents have been requested. Because of this, the Build mode
should only be used together with a complete understanding of
what you are doing.
Using --create would have damaged the data; people who suggested this
just had not understood the question.
I had not noticed this feature of mdadm, thanks for letting me know
about it.
Regards,
--
Nicolas George
