NonStop NS-Series Planning Guide (H06.03+)

Control, Configuration, and Maintenance Tools
HP Integrity NonStop NS-Series Planning Guide—529567-004
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AC Power Monitoring
AC Power Monitoring
Unlike previous NonStop servers that used internal batteries for memory hold-up
through power failures, Integrity NonStop NS-series servers require either the optional
HP model R5500 XR UPS (with one or two ERMs for additional battery power)
installed in each modular cabinet or a user-supplied site UPS to support system
operation through power transients or an orderly system shutdown in a power failure.
If an HP R5500 XR UPS is installed, it is connected to the system’s maintenance 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 EMS
notification of the outage 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 of
time in case the power outage was no more than a momentary transient. One or two
ERMs installed in each cabinet can extend the battery-supported system run-time.
The system user must configure the system ride-through time to execute an orderly
shut-down before the UPS batteries are depleted. The time available for battery
support depends on the state of 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 site UPS is employed rather than the rack-integrated 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 according to the capacity of the site UPS and the power demands made
on that UPS.
The optional Model 5500 XR UPS and ERM installed in Integrity NonStop NS-series
cabinets do not support any devices that are external to the cabinets. External devices
can include tape drives, external disk drives, LAN routers, and SWAN concentrators.
Any external peripheral devices that do not have UPS support will fail immediately at
the onset of a power failure. Plan for UPS support of any external peripheral devices
that must remain operational as system resources. This support can be a site UPS or
individual units as necessary.
This information relates to handling power failures:
•
For ride-through time, see the SCF Reference Manual for the Kernel Subsystem.
•
For TACL SETTIME command, see the TACL Reference Manual.
•
For setting system time programmatically, see the Guardian Procedure Calls
Reference Manual.