Re: adding a disk smaller than the array size

[kclair <kclair@gmail.com>]

On Wed, 13 Oct 2004 18:46:43 -0400, Jim Paris <jim@jtan.com> wrote:
> > And failing everything, you could (maybe) clone the array-disk to the empty
> > smaller one, run fsck to fix the partition size (but I'm not totally sure it
> > does, so that remains doubtful), reverse the roles of the two disks and then
> > add the -now free- larger disk to the array. But that would be a last resort.
> > I cannot vouch for how md copes with the few missing sectors, and neither how
> > the filesystem reacts, so you'd better not try that without good testing.
> 
> Or just do this same thing at the filesystem level.
> 
> Right now you have md0 with one missing disk.  Use your new disk to
> create md1 with one missing disk.  Create filesystem on md1, and copy
> files with e.g. tar, rsync, etc.  Then get rid of md0 and add that
> drive to md1.
> 
> -jim
> 

Thanks for all the info and the suggestions.  The key factor here was
that I could not just build an array with one disk containing the data
and one unformatted disk and hope they would sync up.  I followed
Jim's advice successfully ... except that mdadm reports that the new
array is State: dirty.
But at least the data is accessible once again!

Kristina