I'm setting up a new machine with a pair of IDE drives connected to HPT 370 controller. I defined a RAID-1 array using the HPT370 bios setting utility.
Description - hard:
motherboard Abit ST6-RAID, HPT370, 2 identical hard disks as primary/secondary master on ide3/ide4
- bios:

Primary Master:   Mirror (Raid 1) for Array #0 UDMA 5 78150 BOOT
Primary Slave:    No drive
Secondary Master: Mirror (Raid 1) for Array #0 UDMA 5 78150 HIDDEEN
Secondary Slave:  No drive

- os:
Linux RedHat 7.1 & kernel 2.4.17
with compilation option
CONFIG_BLK_DEV_ATARAID_HPT=y
Lilo:
...
root=/dev/hde10
...

During system booting i see following
...
ataraid/d0: ataraid/d0p1 ataraid/d0p2 ataraid/d0p3 ataraid/d0p4 <> Highpoint HPT370 Softwareraid driver for linux version 0.01 Drive 0 is 76319 Mb
Drive 6 is 76319 Mb
Raid array consists of 2 drivers
...

Kernel panic: VFS: Unable to mount root fs on 21:0a

...

And system stop

Booting with option root=/dev/atarad/d0p1 ro
(or root=/dev/ataraid/d0p10 ro)
and etc - no effect

Any hints?

Hi

The root should be /dev/ataraid/xxx for any ata raid but that is not the real problem...

Ataraid seems to find four partitions d0p[1234]. But as far as I know mirroring isn't supported by the in kernel open source drivers at all - you may look at the closed source drivers at www.highpoint-tech.com, if you really need the "hpt native" raid.
(http://people.redhat.com/arjanv/pdcraid/ataraidhowto.html)

If you just just use need to access the harddisks from linux it is suggested to use linux software raid (there was a discussion at lkml - if I remember right). On modern PCs it uses < 5% CPU and is faster, as it operates high level in the kernel, not right before the hardware, as those "big software part, small hardware part" raid controller from Promise and Highpoint do.

HTH

Jan-Marek