It looks like everything worked. All that was needed was to tell disk utility to "erase" the disks in the raid. It apparently did newfs or mkfs afterward and created the new disk device. I did make the mistake of manually mounting it and guess what, the installer didn't see this as a valid drive any longer since it was mounted so I restarted the system again from the Installation disk and this time the installer saw the new drive andsuccessfully installed MacOS. Thanks to all for the suggestions. I didn't know how close I was to success. The next few days will tell whether the raid is working as it should but all indications are that it is fine. Martin McCormick WB5AGZ Stillwater, OK Systems Engineer OSU Information Technology Department Telecommunications Services Group