OpenVMS Cluster Systems - OpenVMS Systems - HP

IF... THEN...
The startup procedures fail to
complete after a period that is
normal for your site.
You suspect that the value for
the NPAGEDYN parameter is
set too low.
You suspect a shortage of
page file space, and another
OpenVMS Cluster computer is
available.
The computer still cannot
complete the startup procedures.
C.6 Diagnosing LAN Component Failures
Cluster Troubleshooting
C.5 Startup Procedures Fail to Complete
Try to access the procedures from another OpenVMS Cluster
computer and make appropriate adjustments. For example, verify
that all required devices are configured and available. One cause
of such a failure could be the lack of some system resource, such
as NPAGEDYN or page file space.
Perform a conversational bootstrap operation to increase it. Use
SYSBOOT to check the current value, and then double the value.
Log in on that computer and use the System Generation utility
(SYSGEN) to provide adequate page file space for the problem
computer.
Note: Insufficent page-file space on the booting computer might
cause other computers to hang.
Contact your Compaq support representative.
Section D.5 provides troubleshooting techniques for LAN component failures (for
example, broken LAN bridges). That appendix also describes techniques for using
the Local Area OpenVMS Cluster Network Failure Analysis Program.
Intermittent LAN component failures (for example, packet loss) can cause
problems in the NISCA transport protocol that delivers System Communications
Services (SCS) messages to other nodes in the OpenVMS Cluster. Appendix F
describes troubleshooting techniques and requirements for LAN analyzer tools.
C.7 Diagnosing Cluster Hangs
Conditions like the following can cause a OpenVMS Cluster computer to suspend
process or system activity (that is, to hang):
Condition Reference
Cluster quorum is lost. Section C.7.1
A shared cluster resource is inaccessible. Section C.7.2
C.7.1 Cluster Quorum is Lost
The OpenVMS Cluster quorum algorithm coordinates activity among OpenVMS
Cluster computers and ensures the integrity of shared cluster resources. (The
quorum algorithm is described fully in Chapter 2.) Quorum is checked after any
change to the cluster configuration—for example, when a voting computer leaves
or joins the cluster. If quorum is lost, process and I/O activity on all computers in
the cluster are blocked.
Information about the loss of quorum and about clusterwide events that cause
loss of quorum are sent to the OPCOM process, which broadcasts messages
to designated operator terminals. The information is also broadcast to each
computer’s operator console (OPA0), unless broadcast activity is explicitly
disabled on that terminal. However, because quorum may be lost before OPCOM
has been able to inform the operator terminals, the messages sent to OPA0 are
the most reliable source of information about events that cause loss of quorum.
If quorum is lost, you might add or reboot a node with additional votes.
Cluster Troubleshooting C–15