> Subject: RE: Largest drive sizes in MV/VS3100 machines?
> Date: Tue, 3 Dec 2002 14:42:07 -0800
> Thread-Topic: Largest drive sizes in MV/VS3100 machines?
> Thread-Index: AcKa9z7jPcEcu1fyRt+XuKwhHqrjOwAJMzWQ
> From: "Antonio Carlini" <Antonio.Carlini@riverstonenet.com>
> To: "Carl Lowenstein" <cdl@mpl.ucsd.edu>, <port-vax@netbsd.org>
> 
> >That is the address limit of the original 6-byte SCSI command set. 21
> bits of block address ->  2^
> >(21+9) 512-byte blocks = 1.073GB.
> 
> So far so good.
> 
> >Next address limit barrier is the 32-bit character pointer, 
> 
> Yup
> 
> > which cuts off at 4.29GB.
> 
> I think that should be 2^(32-21) bigger than the
> number you first thought of. I was going to say
> that > 2TB is just silly but having seen a 250GB
> drive today at a non-ridiculous price (admittedly IDE
> not SCSI ...) I think I'll be careful to say nothing at all.
> Maybe in a few years I can test that later limit :-)

There's a factor of 2^9 in there because the SCSI address counts
512-byte blocks and the character pointer counts single bytes.

    carl
-- 
    carl lowenstein         marine physical lab     u.c. san diego
                                                 clowenst@ucsd.edu