Raid 1 Issues

[Leif Sawyer]

I'm running 2.4.18, and trying to use Raid-1.

I created /etc/raidtab according to the instructions.
    raiddev /dev/md0
        raid-level      1
        nr-raid-disks   2
        nr-spare-disks  0
        device  /dev/hdc2
        raid-disk       0
        device /dev/hdb2
        raid-disk       1

Next, I performed a raidsetup on my new disk (/dev/hdc2), and restarted.  I
was
able to mount my new md0 with a single disk.

I then migrated all my data onto that new md0 and removed the old disk
(/dev/hdbX)
from /etc/fstab. I changed fstab to mount /dev/md0 as /usr and shutdown.

I removed the old /dev/hdb, and installed the new drive, a duplicate model
of /dev/hdc,
and restarted.  I have no problems accessing /usr at this point, mounted
from /dev/md0.

I partitioned /dev/hdb to be exactly like /dev/hdc, and formatted it as
ext3.
I then used raidhotadd /dev/md0 /dev/hdb2 to try and add the new partition
to
my mirror.

"cat /proc/mdstat"  shows the the devices connected, but not attached:

	Personalities : [raid1] 
	read_ahead 1024 sectors
	md0 : active raid1 ide/host0/bus0/target1/lun0/part2[1]
ide/host0/bus1/target0/lun0/part2[0]
	      77914752 blocks [1/1] [U]
      unused devices: <none>

I waited for a while, installed some software, and then looked at
/proc/interrupts:
root@hedwig:~> cat /proc/interrupts 
           CPU0       
  0:   14635352          XT-PIC  timer
 14:     581245          XT-PIC  ide0
 15:    1341378          XT-PIC  ide1

I have 2 disks on ide0,( / and /dev/hdb2), 2 disks on ide1 (/dev/hdc2 and
/dev/cdrom)

The difference in interrupts is really significant when moving data around.
ide0 doesn't
increment at the rate that ide1 does (nowhere close!) when accessing
/dev/md0 (mounted on /usr)

if I raidhotremove /dev/md0 /dev/hdb2, and then mount /dev/hdb2, there is
nothing on the
disk.

I've consulted the how-to without any success.

Thanks for any help or suggestions.