RE: Requesting replace mode for changing a disk

Neil Brown
2009-05-13T04:31:03Z

On Tuesday May 12, lrhorer@satx.rr.com wrote:
>
> But doesn't creating the array with the drive wipe the contents? If so, it
> doesn't seem to me this provides much redundancy.

No. Creating an array does not wipe the contents.
It might cause a resync which will copy contents from one drive to the
other and I don't promise which one.
However if you:

mdadm -C /dev/md0 --level 1 -n 2 /dev/foo missing
mdadm /dev/md0 --add /dev/bar

then the contents on /dev/foo will not be changed (except for a few K
at the end for the metadata) and then all of foo will be copied to
bar.

NeilBrown