Subject: RE: Highpoint HPT370 IDE raid controller
To: None <port-i386@netbsd.org>
From: Thomas Michael Wanka <Tom@Wanka.at>
List: port-i386
Date: 02/17/2001 17:41:54
Hi,


On 18 Feb 2001, at 2:48, Grant Beattie wrote:

> I just found it strange that it worked under Win2k (with no drivers
> installed), but NetBSD saw them as separate disks.
> 

If I understood it correct, win2k has the drivers installed by default. 
That is, you need to add the Raid drivers for older versions of win 
before you can use the raid controller. Some of these controllers 
seem to do the raid functionality in software (Bios or driver or both). 
NetBSD seems to ignore the software and adresses the controller 
chip that can only see the attached drives. At least some of these 
IDE raid controllers have other problems, I think Toms Hardware 
did a test that showed, that if a drive is mirrored (Raid 0) and the 
primary master fails the system can stall or at least cannot boot 
from the mirrored drive. See 
"http://www4.tomshardware.com/storage/00q1/000329/index.html"

> any form of striping/mirroring/etc will be faster in hardware than
> software, though, surely (?)regardless of OS..

Basically yes, just that the lack of floppies with software run under 
your OS does not necessarily imply it is a hardware solution, if the 
bios or driver contains the software to do the raid functionality it in 
fact is software raid. And if the hardware raid has a controller CPU, 
that cannot handle the amount of data, software raid can be faster 
with the disadvantage of higher CPU load.

mike