Using Asus P5Q Pro raid5, (ICH10R chipset).
I've setup 4 SATA drives in Raid 5 using the motherboard's interface. It shows up in windows fine, without adding software. I've been using them fine for a while.
When I boot to ubuntu (9.04) the drives show up as individual drives. fdisk -l shows them as /dev/sda1 to sdd1, and gparted lists them as "unallocated".
(Ubuntu isn't booting from the raid install; it uses a different drive)
Surely if it's hardware raid ubuntu shouldn't be able to see individual drives, and if it's software I'd have needed to install some software on windows?
Edit:
I installed dmraid on linux.
/dev/mapper now contains an entry "isw_caajecghbe_Array".
dmraid -r shows
/dev/sdd: isw, "isw_caajecghbe_Array", GROUP, ok, (number of sectors), data@ 0
/dev/sdc: isw, "isw_caajecghbe_Array", GROUP, ok, (number of sectors), data@ 0
/dev/sdb: isw, "isw_caajecghbe_Array", GROUP, ok, (number of sectors), data@ 0
/dev/sda: isw, "isw_caajecghbe_Array", GROUP, ok, (number of sectors), data@ 0
dmraid -ay says the raid set is already active.
fdisk /dev/mapper/isw_caajecghbe_Array gives "unable to read"
For the benefit of searchers, this person has an identical problem, only with a slightly different chipset; http://ubuntuforums.org/showthread.php?t=1289290