The OpenVMS V6.2 documentation set contains a manual -- _VMScluster
Support for SCSI Interconnects in OpenVMS Version 6.2_ -- on using SCSI
as a VMScluster system interconnect, and this document should answer all
of your questions.
Thanks for your question! SCSI Clusters are well documented in the OpenVMS
Release Notes and New Features manuals. With all the releases we've been doing
things have got a little scattered, but the best places to start are the V6.2
New Features, and the V6.2-1H2 Release Notes.
You will find that the documentation refers to the KZPAA (single-ended SCSI)
and the KZPSA (FWD SCSI) adapters. There are few (if any) references to the
KZTSA because we added this support right at the end of the V6.2-1H2 release
cycle, and were too late to update the documentation. However, the KZTSA is
simply the TurboChannel version of the KZPSA (which is a PCI adapter). So,
you can consider the KZTSA and KZPSA to be equivalent.
To answer your question, you can indeed consider SCSI Clusters to be
essentially the same as DSSI Clusters. The only difference from the system
management viewpoint is that SCS traffic (such as the Lock Manager) does not go
across the SCSI (as it does the DSSI), rather it must go across another
interconnect (for DEC 3000s, this would be Ethernet/FDDI). This means that you
must enable the LAN cluster driver - PEDRIVER. Do this with the NISCS_LOAD_PEAO
parameter. If you're not into fiddling directly with the parameters,
Cluster_config can be induced to do it for you (off hand, I can't remember
which menu options are needed; let me know if you need help with this and I can
find out).
Your configuration - DEC3000--ba350--DEC3000--BA350--DEC3000 - looks fine, but
don't forget that the KZTSA is a FWD adapter while the disks in the BA350s will
be single ended devices. So you'll need to put DWZZAs (FWD to SE level
converters) into the BA350s to bridge the FWD bus to the SE disks.
I hope this helps. Let me know if you need more information.