The obvious initial step for this is to enforce the partitioning scheme that we do support (ie. PReP can't be on RAID), and I've been testing a partman-prep update with this.
There's also a big part in grub-installer; I'm preparing a proper fix for this there, pending testing to make sure the firmware understands the way the disks are set up in the case of RAID 1 (because we can't support other RAID levels).
The obvious initial step for this is to enforce the partitioning scheme that we do support (ie. PReP can't be on RAID), and I've been testing a partman-prep update with this.
There's also a big part in grub-installer; I'm preparing a proper fix for this there, pending testing to make sure the firmware understands the way the disks are set up in the case of RAID 1 (because we can't support other RAID levels).