Re: What is the largest drive that NetBSD/VAX will support?

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2016-02-19 14:25, Mark Pizzolato wrote:
> On Friday, February 19, 2016 at 12:00 AM, John Klos wrote:
> > > I'm currently setting up a new project. In this case its an
> > > arrangement of SIMH/VAX running on Linux/I386. The host has a Zip100
> > > drive installed. And as it happens I'm wondering, with this issue:
> > > "What is the largest drive that NetBSD/VAX will support?". Conversely
> > > it becomes "What is the smallest drive that NetBSD/VAX will support?".
> >
> > The largest drive it'll support without any extra fuss, I think, would be
> > 2 TB (2^32-1 blocks of 512 bytes each). The smallest, I think, would be one
> > sector.
>
> That is indeed the upper limit.  I can't imagine any amount of 'fuss' which
> could extend it beyond that.  The boundary is based on the fact that the
> MSCP protocol has a 32bit field containing the logical block number (thus
> the 2^32-1) and all sectors are 512 bytes.  This is a limit of the hardware being
> simulated due to the structure of the MSCP protocol.

Noone forces you to use MSCP. There are VAXen with SCSI as well. 
However, disk labels also limit you to 2^32 blocks, or something like 
that, so there are several subsystems that might cause issues with 
larger disks.

	Johnny

--
Johnny Billquist                  || "I'm on a bus
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