Comment 42 for bug 220493

Yes, if you load the dm-raid45 module at boot you should be able to boot from fakeraid (it's my current config in fact). I was able to roll my own live CD with 2.6.24-19 and dmraid using UCK (http://uck.sourceforge.net/) to get this going.

I'm not sure if 8.04.1 will let you, but at long as it has 2.6.24-19 I don't see why not. Even if 8.04.1 includes the fix, the installer still does not support dmraid so you still have to tweak it to get it going (install the dmraid package and "sudo dmraid -ay" to start the array). You could also use rsync to try out the latest daily build of 8.04.1 to find out, that would probably give you the best idea if dmraid will work for you in 8.04.1. https://help.ubuntu.com/community/RsyncCdImage