Re: Help with Fasttrack/100 Raid on Linux

[Wilfried Weissmann <Wilfried.Weissmann@gmx.at>]

Andre Hedrick wrote:
> 
> Wilfried,
> 
> Why a module?

The idea behind that was that, if it is a seperate module, then it would be easier to maintain for
me. I am a guy that always needs the newest and greatest, so I expected that I would have to port my
stuff to newer kernels frequently. (I started the HPT-RAID0 alone without much knowledge about the
kernel.)

> Why not have the detection and flags that hook the md driver for linux and
> use linux's software raid?

I could not use the disk striping, because of the raid0 code is not capable of processing a request
what would span more than one disk. You also have to shift the offset of all but the first disk by
10 sectors. So I created an own personality...

I also guess it would be a bit complicated if we want to create a raid10. Is this done by putting a
raid1 over raid0 devices? We would have to find a way to map the sectors according to the IDE-RAID
spec of the controller over several raid levels.
An ataraid personality would be easier and more flexible then.

regards,
Wilfried

> 
> Cheers,
> 
> On Mon, 16 Apr 2001, Wilfried Weissmann wrote:
> 
> > Arjan van de Ven wrote:
> > >
> > > In article <3AD6B422.EEC092F0@ftel.co.uk> you wrote:
> > > > Andre Hedrick wrote:
> > >
> > > > However as far as I can see everyone who has a FastTrak which is "stuck"
> > > > in RAID mode[1] would be happy if it worked as a normal IDE controller
> > > > in Linux, which is (usually?) not the case - eg on the MSI board where
> > > > only the first channel is seen.
> > >
> > > I have a patch to work around that. However the better solution would be to
> > > have a native driver for the raid; I plan to start working on that next
> > > week...
> >
> > I am doing the same for the HighPoint-Tech 370 (talking about the RAID driver). Disk-striping is
> > working so far. My code is based on the kernel patches for MDs from Neil Brown. I created an own
> > RAID-personality for the module.
> > When I looked at the FreeBSD implementation I had the idea of making a "supermodule" which could
> > contain serveral IDE-RAID drivers (e.g.: Proise FastTrack + HPT370). There would be a super
> > personality for ATA-RAID and several low-level drivers for the individual controllers.
> >
> > Interrested? Ideas? Hints, Tips, ...? Wanna team up? <8)
> >
> > >
> > > Greetings,
> > >   Arjan van de Ven
> >
> > regards,
> > Wilfried
> >
> > PS: An uppercase THANX goes to Nail Brown!

^Nail^Neil

> 
> Andre Hedrick
> Linux ATA Development
> ASL Kernel Development
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-- 
Wilfried Weissmann ( mailto:Wilfried.Weissmann@gmx.at )
Mobile: +43 676 9444465