If planning to install a standard LinuxDistribution onto a box with HardwareRaid, it's a good idea to make sure it is a SupportedRaidController. Unless you are after the fun of making it go, this will save some hassle.
The results of a partly supported controller are not as simple as may be expected. I've seen a server with the built in HardwareRaid turned on and when a custom LinuxDistribution was installed, it ingored the HardwareRaid and installed on to the two SCSI disks directy. This was discovered when pulling out one of the 'mirrored' HotSwappable disks.
For a useful list of supported SATA RAID controllers, try here.
One page links to SupportedRaidController: