One SCSI tape connected to 2 hosts?

From: Doc <doc_at_mdrconsult.com>
Date: Sun Jun 16 15:16:57 2002

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 - 15:16:57 BST