I've redone the installation a few times to verify and gather data/errors. <div class="gmail_quote"> Redhat 5 installs OK. Completely updated to 5.6 and rebooted fine. Debian 6 installs OK. Boots fine. Redhat 6 CDROM netinstaller does not see CDROM drive as possible media source, after having booted from it. Redhat 6 DVD installer has an anaconda error when we select either replacing the partitions or custom. Prior to selecting one of those options the installer produced this warning: Warning disks sda,sdb contains BIOS RAID metadata but are not part of any recognized BIOS RAIDsets. Ignoring disks sda, sdb. In one case the existing RAID had been created by RH5, and in another case of this install trial history, it had a RAID created by Debian 6. We can say OK to the warning, and try the default option to reuse and reformat the existing Linux partition, or chose the custom layout. Either way, there is an anaconda exception: anaconda 13.21.82 exception report Traceback (most recent call first) File "/usr/lib/anaconda/iw/cleardisks_gui.py", line 154, in getScreen selfbootDisk = sorted(names, self.anaconda.id.storage.compareDisks)[0] ... IndexError: list index out of range Eventually we noticed another error on another screen about RAID blocks and it refered to a driver device starting with sil_ My colleague recalled the drives had been taken from a SATA storage bay which had been used with a Silicon Image controller in the past. It seemed unlikely RAID blocks could be present from that long ago, as we had these disks working as a Debian or Redhat 5 with software RAID 1. I used dd to wipe the first part of the drives with zeros and attempted the installation of RH6 from DVD again. Still saw the RAID metadata error. I wiped up to the first 5 GB of the disks, and no difference. Then I left dd running at the end of the day to write zeros right to the end of the drives. (WARNING: the following command wipes all data from disks, including partition tables...) # dd if=/dev/zero of=/dev/sda bs=8192 # dd if=/dev/zero of=/dev/sdb bs=8192 This morning I tried an install and no more errors about the BIOS RAID metadata. The RH 6 install completed and it boots fine as MD RAID 1. There are two flaws in the Redhat installer compared to RH 5 installer. The CDROM installation has problems seeing the very media it booted from, and the scan of the disk for existing RAID metadata has no way of saying lets force use of these disks despite finding some relic of RAID metadata on them. Debian 6 nor Redhat Enterprise 5 had problems reusing the disks while there was still some prior hint of RAID metadata. --Donald </div>