Moving drives around for a new one

["Timothy D. Lenz" <tlenz@vorgon.com>]

I currently have 4 500Gb drives. sda/b are mirrored with 3 arrays:

md0 is boot, os, and some misc stuff.
md1 is swap
md2 is data.

sdc/d is one mirrored array, md3

sdc is failing. SMART is now reporting ~150 bad sectors but mdadm hasn't 
kicked it out yet. I have a Hitachi 0A39289 Ultrastar A7K2000 on order. 
I am hoping that it is not short changed on size compaired to the 2 
segates or it won't have enough space. But I want it to be mirrored into 
all 4 arrays basicly becoming a 3rd mirror for md0/1/2 and one of 2 for 
md3. At some point I want to get a second 1TB and get it down to just 
the 2 drives. Then I can remove md3 and expand md2.

What I'd like to do is after removing sdc, move sda/b down one on the 
motherboard connectors so that the new drive is sda. There is at least 1 
file I know needs to be updated for grub:

/boot/grub/device.map
(fd0)	/dev/fd0
(hd0)	/dev/disk/by-id/ata-ST3500413AS_Z3T69GCE
(hd1)	/dev/disk/by-id/ata-ST3500418AS_5VMJ49P1
(hd2)	/dev/disk/by-id/ata-ST3500320AS_9QM35MY5
(hd3)	/dev/disk/by-id/ata-ST3500820AS_9QM6V6JF

To fix that my notes have "grub-install --recheck /dev/sda" from the 
last drive replacement I did. I'm guessing I need something a bit 
different to update all the drive locations? Maybe:
"grub-install --recheck all"?

But I don't need to do anything for:
menu.lst: http://pastebin.com/7WWHajsc
correct?

What about /etc/mdadm/mdadm.conf:
# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
DEVICE partitions

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR tlenz@vorgon.com

# definitions of existing MD arrays
# ARRAY /dev/md0 level=raid1 num-devices=2 
UUID=e4926be6:8d6f08e5:0ab6b006:621c4ec0
# ARRAY /dev/md1 level=raid1 num-devices=2 
UUID=eac96451:66efa3ab:0ab6b006:621c4ec0
# ARRAY /dev/md2 level=raid1 num-devices=2 
UUID=934b5d12:5f83677f:0ab6b006:621c4ec0
# ARRAY /dev/md3 level=raid1 num-devices=2 
UUID=47b3c905:5121e149:0ab6b006:621c4ec0

ARRAY /dev/md0 UUID=e4926be6:8d6f08e5:0ab6b006:621c4ec0
ARRAY /dev/md1 UUID=eac96451:66efa3ab:0ab6b006:621c4ec0
ARRAY /dev/md2 UUID=934b5d12:5f83677f:0ab6b006:621c4ec0
ARRAY /dev/md3 UUID=47b3c905:5121e149:0ab6b006:621c4ec0