mcintosh@decus.com.au (04/04/91)
We are interested in buying SCSI controllers to go in a dual-host 3400. CMD claim their CQD-240 controller is equivalent to DSSI in that it lets both CPUs have direct connections to SCSI disks. I am a bit concerned about VMS and VAXcluster software support for this configuration. To my understanding VMS does not support SCSI as a cluster interconnect. The only interconnects are CI, NI and DSSI. So how can CMD do it? Is there anyone out there using these controllers in a multi-host environment, as opposed to a single CPU disk and tape controller? Robert McIntosh mcintosh@decus.com.au Australia Post
mike@UC780.UMD.EDU (Mike Santangelo) (04/04/91)
In article <9962.27fb325f@decus.com.au>, mcintosh@decus.com.au writes: >We are interested in buying SCSI controllers to go in a dual-host 3400. CMD >claim their CQD-240 controller is equivalent to DSSI in that it lets both CPUs >have direct connections to SCSI disks. > >I am a bit concerned about VMS and VAXcluster software support for this >configuration. To my understanding VMS does not support SCSI as a cluster >interconnect. The only interconnects are CI, NI and DSSI. So how can CMD do it? > >Is there anyone out there using these controllers in a multi-host environment, >as opposed to a single CPU disk and tape controller? > >Robert McIntosh mcintosh@decus.com.au >Australia Post I've been talking to CMD recently with regard to getting their BI bus SCSI interface. I noted their claim too in an advertisement and asked them about it. It was explained to me as such: They use the LAVC software apparently, fooling it somewhat. Currently, although disk access between the two hosts are done through the SCSI interface, locking is still sent over an ethernet. They claim to be working on this so that everything goes over the SCSI bus. They seem very serious when talking about it that it does indeed work. I am not currently in a position to test it, just my $.02 worth. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Michael F. Santangelo + Inet: mike@uc780.umd.edu VMS / UNIX Systems + mike@socrates.umd.edu Academic Computing UMUC + Bnet: MIKE@UC780 (The University of Maryland, + MIKE@UMUC (not visited often) University College) +<Your clever net-phrase here>