OpenVMS Cluster Systems - OpenVMS Systems - HP

A
Cluster System Parameters
For systems to boot properly into a cluster, certain system parameters must be
set on each cluster computer. Table A–1 lists system parameters used in cluster
configurations.
A.1 Values for Alpha and VAX Computers
Some system parameters for Alpha computers are in units of pagelets, whereas
others are in pages. AUTOGEN determines the hardware page size and records
it in the PARAMS.DAT file.
Caution: When reviewing AUTOGEN recommended values or when setting
system parameters with SYSGEN, note carefully which units are required for
each parameter.
Table A–1 describes system parameters that are specific to OpenVMS Cluster
configurations that may require adjustment in certain configurations. Table A–2
describes OpenVMS Cluster specific system parameters that are reserved for
OpenVMS use.
Reference: System parameters, including cluster and volume shadowing system
parameters, are documented in the OpenVMS System Management Utilities
Reference Manual.
Table A–1 Adjustable Cluster System Parameters
Parameter Description
ALLOCLASS Specifies a numeric value from 0 to 255 to be assigned as the disk allocation
class for the computer. The default value is 0.
CHECK_CLUSTER Serves as a VAXCLUSTER parameter sanity check. When CHECK_
CLUSTER is set to 1, SYSBOOT outputs a warning message and forces
a conversational boot if it detects the VAXCLUSTER parameter is set to 0.
CLUSTER_CREDITS Specifies the number of per-connection buffers a node allocates to receiving
VMS$VAXcluster communications.
If the SHOW CLUSTER command displays a high number of credit waits
for the VMS$VAXcluster connection, you might consider increasing the
value of CLUSTER_CREDITS on the other node. However, in large cluster
configurations, setting this value unnecessarily high will consume a large
quantity of nonpaged pool. Each receive buffer is at least SCSMAXMSG
bytes in size but might be substantially larger depending on the underlying
transport.
It is not required that all nodes in the cluster have the same value for
CLUSTER_CREDITS. For small or memory-constrained systems, the default
value of CLUSTER_CREDITS should be adequate.
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Cluster System Parameters A–1