C
Programming Parameters for DSSI
Devices
This appendix describes the console mode procedures for setting and examining
parameters for DSSI devices.
Note
Before you reprogram DSSI devices, you should have a good
understanding of DSSI architecture and VAXcluster software operation.
If you do not have that understanding, you should read the VMS manuals
listed in Appendix A or call your Digital service representative.
Four CPU DSSI adapters are available for your system: two DSSI adapters on
the CPU module, and two optional DSSI adapters on a DSSI daughter board.
The two DSSI adapters on the CPU are bus 0 and bus 1. The two optional
DSSI adapters on the DSSI daughter board are bus 2 and bus 3. Two additional
adapters are available from the KFQSA.
Each adapter provides a separate DSSI bus that can support up to eight nodes,
where the adapter and each DSSI storage devices count as one node, hence
each DSSI adpater can support up to seven DSSI storage devices (six DSSI
storage devices for a two-system DSSI VAXcluster; five DSSI storage devices for
a three-system DSSI VAXcluster configuration). The adapters make a connection
between the CPU and the requested device on their respective DSSI bus. Each
DSSI device has its own controller and server that contain the intelligence and
logic necessary to control data transfers over the DSSI bus.
Programming Parameters for DSSI Devices C–1
