On Thu, 17 Jun 2010 11:15:11 +0100
David Watson [off-list ref] wrote:

Hello,

Recently I upgraded to 2Tb disks on one of my servers, I built a new
degraded raid1 array:
mdadm --create /dev/md7 -level 1 --raid-devices=2 missing /dev/sdd1

added its entry to /etc/mdadm/mdadm.conf then I rebooted to add the
second disk and added it to the array:
mdadm --manage /dev/md7  --add /dev/sdb1

I updated /etc/mdadm/mdadm.conf, although I noticed no difference in the
output of:
mdadm --detail --scan


I use a monolithic kernel so there is no ramdisk to regenerate. This is
my first 1.00 array, and the existing 0.9 arrays have never shown this
issue. I have attempted the same process on a test server with no
issues, and I can't really think of what to look at next.

apologies for the long post.

Long posts are good....
However I cannot see in your long post what the actual problem is.
You have given no evidence that anything degrades on boot.
No kernel logs, no "/proc/mdstat immediately after boot"...

More info please.

NeilBrown