Subject: Re: VAX 4000 QBUS CI interface? (CIQBA)?
To: Gunther Schadow <gunther@aurora.regenstrief.org>
From: Chuck McManis <cmcmanis@mcmanis.com>
List: port-vax
Date: 06/26/2001 11:59:34
At 01:51 PM 6/26/01 -0500, you wrote:
>Hi,
>
>I'm wondering if I even want a VAX 4000 ever, if it doesn't have a CI
>bus option. On the Compaq web site I find that CI clustering is "N/A".


All of the 4000's I've seen that have been clustered use the SHAC on the 
DSSI bus for the cluster bus. The 4000/300 and above have two DSSI busses 
so you can dedicate one to the cluster traffic and one to storage. The 
KA690 can add an additional two DSSI ports which would let you do a 4 way 
cluster in a star configuration. (don't know if that would be supported 
though!)

--Chuck