One SCSI tape connected to 2 hosts?

From: Clint Wolff <vaxman_at_earthlink.net>
Date: Sun Jun 16 16:27:22 2002

Hi Bob,

I've tried to connect a tape drive between a Windows 95? machine
and a FreeBSD machine with limited success. Windows issues a bus
reset whenever it gets confused (translate a lot!) which will
abort any transfer taking place from the MV3100. FreeBSD seemed
to be better about not bothering with the bus except for reboots,
but wasn't reliable WRT transfers.

What you really need is a PC driver that accepts the fact it isn't
the highest priority device, and leaves the bus reset line alone.

Clint

On Sun, 16 Jun 2002, Doc wrote:

> On Sun, 16 Jun 2002, Bob Lafleur wrote:
>
> > I've noticed that my MV3100's SCSI host ID's are set to 6 - I thought
> > this odd, as host ID's are usually 7. Are all MV3100's set to 6, or is
> > mine unique? Anyway, I thought since my PC's host ID is 7, I could
> > connect my SCSI tape drive to both systems. So I ran a cable from one
> > connector on the back to my PC, and a cable from the other connector to
> > my MV3100. I figure it's a properly terminated chain, as each host
> > controller is terminated (I know the PC is, I assume the MV3100 is).
> >
> > It *seems* to work OK. But can anyone tell me for sure if this is
> > "legal"? I'm sure I'm looking for trouble if I try to use the same tape
> > drive from both systems at the same time, but as long as I don't do
> > that, is this an okay setup? It would sure beat changing cables every
> > time I want to move the tape drive from one system to the other.
>
> Bob,
> A few of the older SCSI "how-to" pages diagrammed just such a setup.
> I've never seen it done in real life, but it always looked like a
> reasonable idea to me, too.
> I just found out, talking to my boss, that both native Solaris and
> Veritas Volume manager support that type of configuration.
> It's also relevant that you can run IP-over-SCSI between hosts, and
> ISTR that the original Beowulf code provided just that for fast
> intra-cluster communication.
>
> Doc
>
>
Received on Sun Jun 16 2002 - 16:27:22 BST