NonStop NS14000 Planning Guide (H06.08+)

System-Down OSM Low-Level Link
In Integrity NonStop NS14000 systems, the maintenance entity (ME) in the VIO enclosures
provides dedicated service LAN services via the OSM Low-Level Link for both OS coldload,
system management, and hardware configuration when hardware is powered up but the OS is
not running. LAN connections are direct from the 10/100 Ethernet ports on the VIO enclosures
to the maintenance switch that is installed in the modular cabinet.
This illustration shows the LAN connections for the OSM Low-Level Link:
AC Power Monitoring
Integrity NonStop NS14000 servers require either the optional HP model R5500 XR UPS (with
one or two ERMs for additional battery power) or a user-supplied UPS installed in each modular
cabinet, or a user-supplied site UPS to support system operation through power transients or
an orderly system shutdown during a power failure.
If an HP R5500 XR UPS is installed, it is connected to the system’s dedicated service LAN via
the maintenance switch where OSM monitors the power state of either AC on or AC off. If a
power outage occurs, OSM starts a ride-through timer and outputs an EMS notification that the
system is running on the UPS batteries. The ride-through timer can be used to let the system
continue operation for a short period in case the power outage was only a momentary transient.
One or two ERMs installed in each cabinet can extend the battery-supported system runtime.
The system user must configure the system ride-through time to execute an orderly shutdown
before the UPS batteries are depleted. The time available for battery support depends on the
charge in the batteries and the power that the system draws.
Additionally, if the site’s air conditioning shuts down in a power failure, the system should be
shut down before its internal air temperatures can rise to the point that initiates a thermal
shutdown. A timely and orderly shutdown prevents an uncontrolled and asymmetric shutdown
of the system resources from depleted UPS batteries or thermal shutdown.
If a user-supplied rackmounted UPS or a site UPS is employed rather than the HP model R5500
XR UPS, the system is not notified of the power outage. The user is responsible for detecting
power transients and outages and developing the appropriate actions, which might include a
ride-through time based on the capacity of the site UPS and the power demands made on that
UPS.
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