Subject: Re: boot blocks - (really DMA M3100/M10 problem)
To: David Brownlee <>
From: John Hayward <>
List: port-vax
Date: 10/04/2000 14:57:24
Dear M3100 Vax People,

Sorry to report that when I attached the B chain to my computer with the
internal drive on the A chain that I experienced problems.  I copied
the kernel from the A chain to the B chain then did diff and chksum on
these files.  They differed.  I could copy a file on the A chain to
another place and do a diff and things appeared to be ok.  Copying files
appeared not to work properly on the B chain to B chain.

Taking the B chain drive back to the original M3100 and that system seemed
to boot and work fine.

The machine with the A chain drive would not boot off of the
drive.  Net-booting then attempting to do a fsck resulted in lots of

The machine with the A chain drives was a working system but it seems to
loose it's date and boot flags when powered down.  There were several
files which I thought I had copied when I set up the machine which did not
appear - this was before attached the B chain drives - so I don't have
100% confidence in this machine.

Bottom line - The fix I have seems to work best with only having drives on
the B chain - NOTE: A chain drives may become corrupted.

I'm doing a low level format at this point and attempt to observe behavior
after re-installing.


 On Tue, 3 Oct 2000, John Hayward wrote:

> Date: Tue, 3 Oct 2000 23:44:22 -0500 (CDT)
> From: John Hayward <>
> To: David Brownlee <>
> Cc: Chuck McManis <>,
> Subject: Re: boot blocks - (really DMA M3100/M10 problem)
> Today I set up a second M3100/M10 which has an internal scsi drive on the
> A chain.  The scsi drive is working without problems.  Maybe tomorrow I
> can attach the external drive and try to see if there are no problems with
> drives on both chains.
> I did note some messages relative to a CD drive about sensing when
> booting (which was on the B chain).
> johnh...
> On Tue, 3 Oct 2000, David Brownlee wrote:
> > Date: Tue, 3 Oct 2000 15:17:55 +0100 (BST)
> > From: David Brownlee <>
> > To: John Hayward <>
> > Cc: Chuck McManis <>,
> > Subject: Re: boot blocks
> > 
> > On Tue, 3 Oct 2000, John Hayward wrote:
> > 
> > > I had a couple of problems - I had unpacked the i386 ALPHA2 sets on my vax
> > > (-{ (big problem) and in switching between net booting and attempting to
> > > boot off the disk entered netbsd for the boot file when the boot flag was
> > > on to prompt for the boot file.  I have since unpacked the vax sets, a
> > > kernel which has the dma offset removed and turned off the boot flag and I
> > > can boot ALPHA2 on my M3100.  It seems faster than running of the network
> > > (maybe because I could hear the disks doing stuff).
> > > 
> > 	Excellent news :)
> > 
> > > I'd still like to know if any one has docs on how the DMA should work on
> > > the 3100 - I'm concerned that the tkxx drive hanging off the scsiA chain
> > > might have dma problems with disks doing dma on the scsiB chain.  I need
> > > to clean my tkxx drives to see if I can get them to work but this is a
> > > lower priority item for me.
> > 
> > 	Do you have a spare disk you can hang off the scsiA chain to
> > 	test them both in parallel?
> > 
> >