d-i with existing software RAID?

[Ross Boylan <ross@biostat.ucsf.edu>]

I have a system that currently has etch installed over software RAID1.
It had md0 made of sda1 and sdb1, and md1 made from sda3 and sdb3.
sd[ab]2 is swap. md0 is /boot, and md1 is / and occupies almost all of
the disk.

I would like to shrink md1, create a new md2 in the freed space, and
then install lenny onto that device.

Is the d-i RC2 an appropriate tool for this?  In particular,
http://www.debian.org/devel/debian-installer/errata says
Auto-assembly of RAID arrays in rescue mode can corrupt data
        Rescue mode should be used with great care when software RAID
        arrays were in use on the system to rescue. The rescue mode
        scripts automatically assemble arrays, which could lead to data
        corruption in the presence of invalid or obsolete RAID
        superblocks. 
        
Since I have 2 distinct md0 devices, I'd hate to have it try to build
something out of all 4 physical disk partitions or, e.g., sda1+sdb3.  On
the other hand, I don't think I have any obsolete or invalid RAID
superblocks (is there a way to check?).

I have similar doubts about other tools (e.g., Knoppix) that I might use
to shrink the partitions.

If d-i is not appropriate, can anyone suggest a safer route?

I would prefer to keep the etch installation both because the vendor
might have put something useful there and because it would be good to
have a backup system and an etch system.

Thanks.
-- 
Ross Boylan                                      wk:  (415) 514-8146
185 Berry St #5700                               ross@biostat.ucsf.edu
Dept of Epidemiology and Biostatistics           fax: (415) 514-8150
University of California, San Francisco
San Francisco, CA 94107-1739                     hm:  (415) 550-1062