State of RAID (and the infamous FastTrak100 card)

State of RAID (and the infamous FastTrak100 card)

[Phil Edwards]

[I am not subscribed at the moment (don't ask :), so please cc me.]

A few months ago there was a brief discussion about the FastTrak100 card
and the driver that Promise provides, and just what all can (technically)
be done.  It eventually became a debate about what may (legally) be done
with the driver, and then turned into another "what the GPL /really/
says" thread.  :-)

I've just read all those messages from the archives.  And I've been
skimming the RAID-related HOWTOs at linuxdoc.org, but many seem out of date.
One in particular starts off by saying that the stock 2.2 support is buggy,
and that the "new" version is much improved, but requires patches and a
rebuild, and is still alpha code.  Of course, the doc saying it's alpha
is itself a year old.

The MAINTAINERS and Documentation/* files don't mention the FastTrack100
(not surprising, it's not OSS) nor software RAID (also unsurprising,
it's software).


So... am I just begging for pain if I try to install, say, a stock RH7
on a machine with the FastTrak100 doing it's little RAID0/JBOD thing?
If it requires this machine to always boot from a floppy because the driver
cannot be linked into the kernel, well, I'm okay with that.

RH7 ships with 2.2.16.  Is building a new 2.2.18 kernel just going to
shoot me in the head with this card (and Promise's proprietary driver)?

What's the state of RAID in the 2.4 kernels?

I'm very leery of solutions that involve lots of patches to the 2.2.x kernel,
because I have to have a working system in order to rebuild a kernel... and
I would have to patch the kernel before I can install/boot the system... and
there will be no other hard drives available in the machine; just the two
being striped (or glued) by the FastTrak100 Card of Doom.


Much thanks,
Phil

-- 
pedwards at disaster dot jaj dot com  |  pme at sources dot redhat dot com
devphil at several other less interesting addresses in various dot domains
The gods do not protect fools.  Fools are protected by more capable fools.

Re: State of RAID (and the infamous FastTrak100 card)

[Jakob Østergaard]

On Wed, Mar 14, 2001 at 03:58:01PM -0500, Phil Edwards wrote:
> [I am not subscribed at the moment (don't ask :), so please cc me.]
> 
> A few months ago there was a brief discussion about the FastTrak100 card
> and the driver that Promise provides, and just what all can (technically)
> be done.  It eventually became a debate about what may (legally) be done
> with the driver, and then turned into another "what the GPL /really/
> says" thread.  :-)
> 
> I've just read all those messages from the archives.  And I've been
> skimming the RAID-related HOWTOs at linuxdoc.org, but many seem out of date.
> One in particular starts off by saying that the stock 2.2 support is buggy,
> and that the "new" version is much improved, but requires patches and a
> rebuild, and is still alpha code.  Of course, the doc saying it's alpha
> is itself a year old.

Ok, I get the feeling it may be the Software-RAID howto you're referring to
here...  Let me explain why it's  not  updated.

Fact is, I haven't updated the document because 99% of what it says is still
the perfect truth.

Software-RAID in 2.2 is buggy and requires patching to go to the so-called
alpha versions (which the HOWTO explains are not alpha-quality but actually
quite usable).

However, 2.4 is out and doesn't need patching, and I should probably update the
howto to reflect that.  But still, most of what's in the HOWTO is as correct as
it can be.

> 
> The MAINTAINERS and Documentation/* files don't mention the FastTrack100
> (not surprising, it's not OSS) nor software RAID (also unsurprising,
> it's software).

FastTrack100 RAID *is* software RAID - The software is in the proprietary
drivers for the card.

But it's confusing, and Andre Hedrick has already explained this mess on
several occations here on LKML.   Search the archives.

> 
> So... am I just begging for pain if I try to install, say, a stock RH7
> on a machine with the FastTrak100 doing it's little RAID0/JBOD thing?
> If it requires this machine to always boot from a floppy because the driver
> cannot be linked into the kernel, well, I'm okay with that.

I don't know about the state of the FastTrak100 IDE drivers - but if you can
get that running, putting software RAID on top of that should be a simple
matter.

> 
> RH7 ships with 2.2.16.  Is building a new 2.2.18 kernel just going to
> shoot me in the head with this card (and Promise's proprietary driver)?

RH 2.2 kernels have "real" software RAID -  stock 2.2  needs patching.

> 
> What's the state of RAID in the 2.4 kernels?

Good.  No patches needed - software RAID in 2.4 rocks.   And 2.4 supports more
IDE controllers - but again I don't know the state of FastTrak100.

> 
> I'm very leery of solutions that involve lots of patches to the 2.2.x kernel,
> because I have to have a working system in order to rebuild a kernel... and
> I would have to patch the kernel before I can install/boot the system... and
> there will be no other hard drives available in the machine; just the two
> being striped (or glued) by the FastTrak100 Card of Doom.

Use plain RedHat kernels, or patch your own  :)

You can boot on software RAID - it's in the HOWTO  ;)

-- 
................................................................
:   jakob@unthought.net   : And I see the elder races,         :
:.........................: putrid forms of man                :
:   Jakob Østergaard      : See him rise and claim the earth,  :
:        OZ9ABN           : his downfall is at hand.           :
:.........................:............{Konkhra}...............:

Re: State of RAID (and the infamous FastTrak100 card)

[Wilfried Weissmann]

Jakob Østergaard wrote:
> > So... am I just begging for pain if I try to install, say, a stock RH7
> > on a machine with the FastTrak100 doing it's little RAID0/JBOD thing?
> > If it requires this machine to always boot from a floppy because the driver
> > cannot be linked into the kernel, well, I'm okay with that.
> 
> I don't know about the state of the FastTrak100 IDE drivers - but if you can
> get that running, putting software RAID on top of that should be a simple
> matter.

I do not think that would work. These IDE RAID use a slightly different layout that someone would
expect. This means that you cannot map it 1:1 to any RAID personality, therefore you cannot boot
from it.

(Free)BSD supports this IDE RAID controller with the RAID functionality. Maybe you want to check it
out.
I want to write a kernel module for 2.4 which supports the HPT370 RAID. You can be sure that I will
peek at the FreeBSD code. In fact that is the only documentation I have.

Wilfried

Re: State of RAID (and the infamous FastTrak100 card)

[Thomas Dodd]

Wilfried Weissmann wrote:
> 
> Jakob Østergaard wrote:
> > > So... am I just begging for pain if I try to install, say, a stock RH7
> > > on a machine with the FastTrak100 doing it's little RAID0/JBOD thing?
> > > If it requires this machine to always boot from a floppy because the driver
> > > cannot be linked into the kernel, well, I'm okay with that.
> >
> > I don't know about the state of the FastTrak100 IDE drivers - but if you can
> > get that running, putting software RAID on top of that should be a simple
> > matter.
> 
> I do not think that would work. These IDE RAID use a slightly different layout that someone would
> expect. This means that you cannot map it 1:1 to any RAID personality, therefore you cannot boot
> from it.
> 
> (Free)BSD supports this IDE RAID controller with the RAID functionality. Maybe you want to check it
> out.

Jakob ment the kernel software-RAID, md.0, raid0.o, raid1.o, raid5.o,
and linear.o
Not the Promise RAID software.

	-Thomas

Re: State of RAID (and the infamous FastTrak100 card)

[Phil Edwards]

On Wed, Mar 14, 2001 at 11:27:14PM +0100, Jakob Østergaard wrote:
> However, 2.4 is out and doesn't need patching, and I should probably update the
> howto to reflect that.  But still, most of what's in the HOWTO is as correct as
> it can be.

Okay, I might give that a try.  I'm still scared of 2.4 due to the reports
of filesystem corruption.  (This data is critical, and restoring 80GB of
stuff from tapes on a pseudo-regular basis would not be cool.)

I'm under the impression that I need to do the RAID at either the card
level ("hardware" or "software", whichever we call it), or the software
level described in the HOWTO, but not both...?

(The process under Linux seems to be quite different so far from how we
do it under, say, Solaris, so I might be way off already.)


> > The MAINTAINERS and Documentation/* files don't mention the FastTrack100
> > (not surprising, it's not OSS) nor software RAID (also unsurprising,
> > it's software).
> 
> FastTrack100 RAID *is* software RAID - The software is in the proprietary
> drivers for the card.
> 
> But it's confusing, and Andre Hedrick has already explained this mess on
> several occations here on LKML.   Search the archives.

I did and didn't find much.  What word am I missing in the search terms?
(I found the FastTrak100->what's-the-meaning-of-the-GPL thread I mentioned,
but nothing else.)


Much thanks,
Phil

-- 
pedwards at disaster dot jaj dot com  |  pme at sources dot redhat dot com
devphil at several other less interesting addresses in various dot domains
The gods do not protect fools.  Fools are protected by more capable fools.