On Fri, 13 May 2011 00:37:02 -0500 "Leslie Rhorer" [off-list ref]
wrote:

quoted

-----Original Message-----
From: NeilBrown [mailto:neilb@suse.de]
Sent: Thursday, May 12, 2011 8:21 PM
To: lrhorer@satx.rr.com
Cc: linux-raid@vger.kernel.org
Subject: Re: New device for RAID array

On Thu, 12 May 2011 19:59:01 -0500 "Leslie Rhorer" [off-list ref]
wrote:

quoted

I read through the man page for mdadm a couple of times and did not spot

how

quoted

to do this.  I currently have a RAID array that I need to upgrade from

1T

quoted

drives to 3T drives.  To accomplish this, I intend to create a larger

array,

quoted

but with fewer spindles, and then rsync the contents of the old array to

the

quoted

new.  Once I am done, I then want to stop the old array (/dev/md0) and

start

quoted

up the new array under /dev/md0.  Do I have to stop the array and then
re-create it with all the same parameters, except the device target?

For v0.90:  --update=super-minor
For v1.x    --update=name

	Um, it will be a 1.2 array, so I take it if the current array is
/dev/md0, named RAID-Server:0 from /dev/sd[a-n], and the new array is
something like /dev/md4, named RAID-Server:4 from sd[q-x], then I stop both
arrays and enter 

mdadm --assemble /dev/md0 /dev/sd[q-x] --update=name

	Correct?  Of course then I need to update /etc/mdadm/mdadm.conf and
run `update-initrd`.

Yes, though you don't really need to change the name on the array unless you
particularly want to.  Just changing mdadm.conf is enough to get it assembled
as the "right" place.

I think the command you give will store "RAID-Server:0" in the metadata
assuming 'hostname' or HOMEHOST in mdadm.conf is RAID-Server, but if it
doesn't you can experiment with explicitly setting --name and --hostname on
the command line.

NeilBrown