Raidutils needs the i2o_config module so adding a line to /etc/modeprobe.conf
alias scsi_hostadapter i2o_config
is one way to do this.
The raidutils-0.0.6 source tar has char special device for the i2o config as /dev/i2o/ctl but the device is /dev/i2octl in RHEL-4. There is a debian patch that fixes this raidutils_0.0.6-3.1.diff.gz or you can symlink /dev/i2o/ctl to /dev/i2octl in a boot script and leave the raidutil sources unpatched.