md: can not impport hdb1, has active inodes!

["Chris Evans" <chris1@psyctc.org>]

Debian stable 2.4.19 kernel with RAID1 compiled in, VIA EPIA CL1000 
motherboard, 2 Maxtor DiamondMax 9 7200rpm 80Gb drives as /dev/hdb 
and /dev/hdc from onboard controller.

I've followed the guide at:
http://www.cs.montana.edu/faq/faqw.admin.py?query=Convert+Root+System+
to+Software+Raid&querytype=simple&casefold=yes&req=search

which had turned up on a debian list search to try to set up the 
RAID1 mirror of the boot/root drive.  I installed to /dev/hdb1 
(/dev/hda is the CDROM and perhaps I should have changed that first). 

Loaded 2.2.20, got 2.4.19 sources, compiled RAID1 support into the 
kernel (still can't get rid of one complaint about a missing 
character set module but don't think that's causing any real 
problems), made the identical /dev/hdc1 into a somewhat smaller linux 

autodetect RAID format partition, mounted it as 2nd drive in a RAID1 
drive using:
  mdadm --create /dev/md0 --level=1 --raid-disks=2 missing /dev/hdc1
which worked fine, mkfs -t ext3 /dev/hdc1, mount it to /mnt1, 
cp -ax / /mnt, tweak /etc/fstab ... /dev/md0 mounts fine, tweak lilo 
conf to boot from /dev/md0, reboot -- fine, finally come to add 
/dev/hdb1 into the array after resetting the partition type to 
autodetect RAID ... 

.. no go, system complains that /dev/hdb1 is mounted or that an inode 

is active:
md: can not impport hdb1, has active inodes!
md: error, md_import_device() returned -16

I assume that's because the boot is still from /dev/hdb but if so, 
how come the howto says this should work.  Seems that nothing I do 
can shift this and if I set the partition back to linux I find I 
can't mount the drive despite rebooting as I get:

mount: /dev/hdb1 already mounted or /mnt1 busy

/mnt1 isn't busy (I can create a completely new mount point: no 
difference) and mount shows that /dev/hdb1 isn't mounted.

I've tried all sorts of tweaking with lilo.conf to remove any calls 
to /dev/hdb but either these don't change anything, or else lilo 
complains that it can't install to the target (e.g. /dev/md0).

I've read through the docs and man pages and done some 
searching around but can't find any explanations.

Help of any sort, including direct pointers to what I've missed or 
misread, desperately needed!

Chris

PSYCTC: Psychotherapy, Psychology, Psychiatry, Counselling
   and Therapeutic Communities; practice, research, 
   teaching and consultancy.
Chris Evans & Jo-anne Carlyle
http://psyctc.org/ Email: chris@psyctc.org