11.2 SYSGEN Parameters for SYS$PBDRIVER
In most cases, the default settings for SYS$PBDRIVER should
be appropriate, however several SYSGEN parameters are
provided. Two SYSGEN parameters control SYS$PBDRIVER:
SMCI_PORTS and SMCI_FLAGS.
11.2.1 SMCI_PORTS
The SMCI_PORTS SYSGEN parameter controls initial load-
ing of SYS$PBDRIVER. This parameter is a bitmask such
that the bits 0 through 25 each represent a controller letter.
If bit 0 is set, PBAx will be loaded. This is the default setting.
If bit 1 is set, PBBx will be loaded, and so on all the way up
to bit 25 will cause PBZx to be loaded. For OpenVMS Alpha
Version 7.2, we recommend leaving this parameter at the
default value of 1.
Loading additional ports allows for multiple paths between
Galaxy instances. For OpenVMS Alpha Version 7.2, having
multiple communications channels does not provide any ad-
vantages because SYS$PBDRIVER will initially not support
Fast Path. A future release of OpenVMS will provide Fast
Path support for SYS$PBDRIVER. When Fast Path support
is enabled, instances with multiple CPUs can get improved
throughput by having multiple communication channels
between instances.
11.2.2 SMCI_FLAGS
The SMCI_FLAGS SYSGEN parameter controls operational
aspects of SYS$PBDRIVER. The only currently defined flag
is bit 1. This controls whether or not the port device supports
communications with itself. Supporting SCS communications
to itself is primarily used for test purposes. By default, this bit
will be turned off and thus support for SCS communication
locally is disabled which saves system resources. This pa-
rameter is dynamic and by turning this bit on, an SCS virtual
circuit should soon form.
Bit Mask Description
0 0 0 = Do not create local communications channels
(SYSGEN default). Local SCS communications
are primarily used in test situations and not
needed for normal operations. Leaving this bit
off saves resources and overhead. 1 = Create
local communications channels.
1 2 0 = Load SYS$PBDRIVER if booting into both a
Galaxy and a Cluster (SYSGEN Default).
1 = Load SYS$PBDRIVER if booting into a
Galaxy.
2 4 0 = Minimal console output (SYSGEN default)
1 = Full console output, SYS$PBDRIVER
will display console messages when creating
communication channels and tearing down
communication channels.