Subject: Re: uVAX-II success!
To: Aaron J. Grier <agrier@poofy.goof.com>
From: Anders Magnusson <ragge@ludd.luth.se>
List: port-vax
Date: 01/19/1999 08:43:23
> 
> One question, though... my RD53 gets detected as an RD51 on bootup:
> 
> [SNIP]
> NetBSD 1.3I (GENERIC) #2: Sat Dec 19 21:23:38 CET 1998
>     ragge@subzero:/multi/src/sys/arch/vax/compile/GENERIC
> [SNIP]
> mscpbus1 at uda0: version 10 model 7
> mscpbus1: DMA burst size set to 4
> ra0 at mscpbus1 drive 0: RD51
> [SNIP]
> 
That means that the disk _is_ a RD51 :-) Actually, the MSCP driver asks 
the disk which type it is, and the disk seems to answer RD51. You can
see how the decoding of disk types is done in vax/mscp/mscp.h.

But the disk type is just informational. The driver also ask the disk
which size it has (cyls, sectors, tracks etc...) and uses that as the
geometry information. If you type "disklabel ra0" you will see what
size the disk is assumed to be.

There are a lot of third-party disks/controllers that always tells that
the disk is a RA81, but gives the correct geometry. So the type of 
disk doesn't say anything important.

-- Ragge