Re: Requesting replace mode for changing a disk

Neil Brown [off-list ref] writes:

On Tuesday May 12, lrhorer@satx.rr.com wrote:

quoted

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

But as the disk is already part of a raid those few K at the end would
be the critical meta data of the original raid.

This only works with a raid without metatada.

MfG
        Goswin