This morning when I booted up my computer, I was greeted by a delightful SMART status report, informing me that one of the disks that makes up my RAID 0 array was about to fail.
After making sure all of my backups were up to date and valid (backups only work if you can actually read them later…), I decided to simply wipe the RAID array, and rebuild my system using the remaining hard drives, in SATA mode.
Well…this didn’t exactly work out like planned. After resetting the drives to non-RAID status, the Ubuntu 11.10 installer wouldn’t detect them. Any of them. The screen that normally gives partition options was completely blank.
I formatted the drives, I re-added them to a RAID array, I set them up to initialize in IDE compatibility mode, I told the installer to not use RAID (by hitting F5 during boot into the live install), I zero’d the drives, I did just about everything. The disks remained depressingly absent from the partitioning screen, despite being able to see them in the disk utility, gparted, and via the command line fdisk utility.
Finally, I ran across an article in AskUbuntu which gave the command for deleting RAID flags/metadata from a hard drive.
sudo dmraid -rE
After running this command, and answering the “Do you really want to erase “sil” ondisk metadata on /dev/sda” question with a yes, I was able to restart the installation process with no problem.