It's great when ubuntu lucid detected my fakeraid several months ago though I have slight suspect it was also broke my one of array disk later. Now for stupid reason I need to move my ubuntu from dedicated OSes disk into one of my storage disks (now non-RAID). Surprise! it can't find root partition... The RAID is gone (from BIOS) but finally after googling a while there is a metadata that written in array disk that need to be cleared.
OK so how I able to type dmraid if I got no accessible Ubuntu? Tell me if I can use Ubuntu rescue mode... but I already use OpenRC liveCD instead. And here is how:
--> this should show where raid metadata written in the affected disks
dmraid -r /dev/sda -E
--> this should strip metadata on each disks mentioned before
you need sudo if not root already
At first I was scare to enter those commands as I've no backup supply at the moment (what if it erase my partition table / bootloader?) but hey it works! it's totally safe :)