Adaptec AAA-13x RAID

[Matthew J. Brodeur]

   I also happen to be of the mind that IDE = BAD.  I have to wonder, do
the IDE RAID cards suck up an IRQ for _EVERY_ channel? I'd much rather
have 15 drives/1 IRQ than 1/1.
   More to the point, I already have the AAA-131SA and 24lbs of
full-height UW-SCSI drives.  Since the system is being dedicated to that
file store, I didn't feel quite SO bad running NT on it.  I did end up
sacrificing a mouse and 32MB more memory than I had planned on using,
though.

   The fate of the Linux drivers for this card is unfortuneate. Is there
any reason Adaptec is so protective of this line?  Were the other drivers
(the AAC series) developed with Adaptec's help, or were they reverse
engineered?


-- 
     -Matt

If at first you don't succeed, destroy all evidence that you tried.


On Wed, 13 Dec 2000, Michael Bilow wrote:

> You do not really get much with such "hardware" RAID controllers under
> Linux.  As far as I know, all of the low-priced ones actually do software
> RAID, and they come with drivers to provide software RAID under Windows or
> whatever.  While they work with Linux, their primary value is in providing
> additional physical IDE channels at non-conflicting addresses.  Since only
> one drive per IDE channel can be active at thr same time, putting two
> drives which participate in the same RAID set onto the same physical IDE
> channel would introduce a substantial performance penalty.
>
>snip<
> In order to provide enough physical IDE channels for efficient software
> RAID under Linux, these specialized "hardware" RAID controllers can be
> very helpful.  Other than that, I am not sure they are worthwhile.  You
> can never get IDE devices to hot-swap, for example.
>
> None of this reasoning applies to SCSI, it is important to note.  With
> SCSI, there is essentially no performance bottleneck which results from
> connecting multiple devices, even those which participate in the same RAID
> set, using the same SCSI bus.  In extreme cases, there are certainly
> issues with doing this, but in practice the concern is not significant
> because the speed of a modern SCSI bus is several times faster than the
> sustained data rate of any disk drive.  SCSI, at least with devices that
> all support disconnection, is quite efficient at sharing bus bandwidth.
>
> -- Mike
>
>
> On 2000-12-13 at 20:10 -0500, Randall Hofland wrote:
>
> > I thought it worth noting that several modest hardware RAID options for IDE are
> > available and a more advanced unit is in the works. ABIT makes an inexpensive 2
> > channel/4 device 0+1 RAID PCI card using the Highpoint controller chipset
> > (about $40-$50) and they have LINUX drivers plus their Gentus LINUX, Promise
> > makes a more expensive but otherwise similar PCI card and there is a new unit
> > coming out with 4 channel/8 device that sounds really hot but I haven't seen it
> > yet on Pricewatch. Abit and other also have the ATA/100-RAID options built into
> > some of their boards: I highly recommend the Abit KT7-RAID as a great low cost
> > option.
> >
> > Michael Bilow wrote:
> >
> > > I was actively involved with this and many of those messages might have
> > > been written by me.  There is not and never will be 7810 support in Linux
> > > while Adaptec provides documentation for it only under non-disclosure.
> > >
> > > Note that new-style software RAID in the kernel is quite solid.  You would
> > > not get hot-swap, but the basic advantages of RAID are there.  Considering
> > > the prices of large IDE drives these days, using software RAID over a bank
> > > of IDE drives is worth considering.  At today's prices, $500 would buy you
> > > two Maxtor Diamondmax 80GB IDE drives which could be mounted on the two
> > > channels of a standard motherboard for RAID-1.
> > >
> > > -- Mike
> > >
> > > On 2000-12-07 at 12:34 -0500, Matthew J. Brodeur wrote:
> > >
> > > >    Does anyone know if there is or ever will be support for the Adaptec
> > > > AAA series RAID controllers under Linux?  The one I have is the AAA-131SA,
> > > > UW single channel SCSI.  The aic7xxx driver recognizes the SCSI channel
> > > > (7880), but produces an unhappy message about not supporting  the array
> > > > controller (7810).
> > > >    I did some searching, but all I found were old messages indicating that
> > > > no work was being done on a driver. Is this still the case?
>

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