Technical data

System Management Release Notes
5.9 OpenVMS Cluster Systems
5.9 OpenVMS Cluster Systems
The release notes in this section pertain to OpenVMS Cluster systems.
5.9.1 New Error Message About Packet Loss
V7.3
Prior to OpenVMS Version 7.3, an SCS virtual circuit closure was the first
indication that a LAN path had become unusable. In OpenVMS Version 7.3,
whenever the last usable LAN path is losing packets at an excessive rate,
PEDRIVER displays the following console message:
%PEA0, Excessive packet losses on LAN Path from local-device-name -
_todevice-name on REMOTE NODE node-name
This message is displayed when PEDRIVER had to recently perform an
excessively high rate of packet retransmissions on the LAN path consisting
of the local device, the intervening network, and the device on the remote node.
The message indicates that the LAN path has degraded and is approaching,
or has reached, the point where reliable communications with the remote node
are no longer possible. It is likely that the virtual circuit to the remote node
will close if the losses continue. Furthermore, continued operation with high
LAN packet losses can result in significant loss in performance because of the
communication delays resulting from the packet loss detection timeouts and
packet retransmission.
Take the following corrective steps:
1. Check the local and remote LAN device error counts to see if a problem exists
on the devices. Issue the following commands on each node:
$ SHOW DEVICE local-device-name
$ MC SCACP
SCACP> SHOW LAN device-name
$ MC LANCP
LANCP> SHOW DEVICE device-name/COUNT
2. If device error counts on the local devices are within normal bounds, contact
your network administrators to request that they diagnose the LAN path
between the devices.
If necessary, contact your Compaq Support representative for assistance in
diagnosing your LAN path problems.
For additional PEDRIVER troubleshooting information, see Appendix F of the
OpenVMS Cluster Systems manual.
5.9.2 Class Scheduler in a Mixed Version Cluster
V7.3
When using the new permanent Class Scheduler in a mixed-version cluster
environment with nodes running OpenVMS Alpha Version 7.2x, the SMISERVER
process on these nodes aborts when you issue any SYSMAN CLASS_SCHEDULE
subcommand that involves those nodes.
If this happens, you can quickly restart the SMISERVER process on those nodes
with the following command:
@SYS$SYSTEM:STARTUP SMISERVER
System Management Release Notes 5–13