On my home computer I have my /home and / partitions setup as software RAID0 
devices using mdadm.  I've found the following discrepancy:  According to the 
output of mount and my mdadm.conf file, /dev/md0 is the location of the RAID 
device for / and /dev/md1 is the location of the RAID device for /home, but 
if I run 'mdadm --examine --scan' I get

ARRAY /dev/md1 level=raid0 num-devices=2 UUID=8f70...
ARRAY /dev/md2 level=raid0 num-devices=2 UUID=0dfb...

showing them as md1 and md2, respectively.  This information is, I believe, 
what must be written on the MD superblock.  Is there a way to change this 
info on the MD superblock without damaging the data on the RAID?

Why do I care?  Well, during a recent distro upgrade (from Ubuntu Edgy (6.10) 
to Ubuntu Feisty (7.4) ) my system ended up in the state where it couldn't 
boot up.  I believe that during the system tried to build a new mdadm.conf 
for the boot image using the ouput of 'mdadm --examine --scan', which put / 
in a different place so that GRUB couldn't find it during boot.  This was an 
unpleasant experience.  It seems like the surest way to avoid anything 
similar in the future would be to get all the places on my system to agree as 
to the location of these devices.

Thanks,

Nick

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