software raid on a powerpc machine
"Over 6 months" but better late than never; and, albeit 5 and a half years later (i.e. one would think newer kernel and open firmware might help), there is still trouble getting software RAID to work on a powerpc machine (e.g. seems to install but on reboot, you get an error about "unknown or corrupt filesystem").
The new Debian 5 installer totally helps set up RAID *as a part of the* installation (and I'm assuming other flavors do as well). In the partitioning step: 1) leave the 32KB apple partition (which won't be there if you have a non-Mac powerpc), 2) make a 1MB "NewWorld Apple partition" and bootable (or PReP for non-Mac), 3) whatever size "physical volume for RAID", 4) repeat the same thing for the second drive, 5) then setup RAID.
When you reboot at the end of the installer, boot back to the CDROM and "rescue" install, then get into a shell from your /dev/md0 so that we can fix the yaboot process (but not sure about cjcone's lilo, as non-Mac also have yaboot, at least for Debian):
# note the output of both
# change "partition=0" to "partition=3" (or "2" if non-Mac powerpc)
# insert "append="md=0,/dev/sda3,/dev/sdb3"" (or "2"s for non-Mac powerpc)
# insert "device=/pci@80000000/pci-bridge@d/ADPT,2940U2B@4/@0:" (my output)
cp /etc/yaboot.conf /etc/yaboot.sda.conf
cp /etc/yaboot.conf /etc/yaboot.sdb.conf
# change "boot=/dev/sda2" to "boot=/dev/sdb2" (or "1" for non-Mac powerpc)
# change the "device=" line to reflect the second output above)
ybin -C /etc/yaboot.sdb.conf
ybin -C /etc/yaboot.sda.conf
Reboot and you should be fine and note: if you use IDE (and not SCSI), you can just use "hd:" for both devices, which is a generic reference to the first IDE hard drive the open firmware finds (as opposed to the output from the ofpath command), which will work for both .conf files (and the sda and sdb will be hda and hdb).