I've been playing around with raidframe a bit recently to figure out
what my ideal configuration for the task at hand is, and I've run into
a couple of things that I was unable to get working, so I'm not sure
if they're unsupported, or if I was just doing it plain wrong.

In all the configs, my goal was to be able to have the root filesystem
on the raid set.  I'm using port-i386, so I know that some of the
configs aren't supported in the bootblocks, so I'm booting the
kernel off a small FFS, and forcing the root fs onto the raid in the
kernel with

config netbsd root on raid0a type ffs

in the kernel config.

(scenario #1)
I have four disks, and want the best performance (with some failure 
recovery, so straight RAID0 is out), so my first thought was to create
two RAID0 filesystems and mirror them with RAID1.  I got the raid0s and
raid1 created, but when autoconfig time rolls around, only the RAID0s 
were configured, and thus it couldn't find the root fs.... is this to 
be expected?  Is there any way I can get the RAID1 autoconfigured at
boot time?

(scenario #2)
The second thing I tried was to set up a RAID5 of the four disks.  Since
I only have four disks total, I wanted to set up the raid5 with three
disks and a "dummy", so I could create a degraded raid5 that I could 
add the fourth disk to once I copied the system to the new raid5.  I have
gotten this to work successfully with RAID1 before, but raidframe would
not let me configure (even with -C) the 4-disk raid5 with only 3 disks.
Is this expected?  

Any feedback/input would be most appreciated... I've now got it running
a 3-disk raid5, but the write performance is so bad I'm considering
other options.  I'd prefer scenario #1 if I can do it, but my next
try will probably be two separate raid1 arrays... I suppose this will
be a good enough compromise.

Thanks!
-- 
Jeff Rizzo                                         http://boogers.sf.ca.us/~riz