How to debug >2GB memory issues (and 3ware)

John-Mark Gurney gurney_j at
Mon Nov 8 15:21:25 PST 2004

Claus Guttesen wrote this message on Mon, Nov 08, 2004 at 20:37 +0100:
> > I have a Dual 4GB system with a 3ware SATA
> > controller that's working
> > properly as long as I restrict it to 2GB with:
> >    hw.physmem=2G
> > Obviously, I'd like to have access to the other 2GB
> > of RAM.  But
> > if I go past 2GB, I get random crashes during all
> > builds (world,
> > kernel, port).
> I can't help you with that particular question, but I
> had issues with a Dell-server and 4 GB RAM which was
> resolved the same way. Maybe a list of drivers that
> are 2GB-, 4GB-ready etc. It's getting more and more
> common to have 4+ GB.

Not sure about 2GB, since that seems like someone is handling a
signed value incorrectly or something like that, but there is the
busdma status page at:

If the driver has been busdma'ified, then it should handle >4GB memory
w/o troubles..  If it is still having data corruption issues, it might
be because the card can't handle the memory range that the drive thinks
it can...

  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."

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