NonStop NS2200 Series Planning Guide

AC Power Monitoring
IMPORTANT: You must change the ride-through time for an HP-supported UPS from the
manufacturing default setting to an appropriate value for your system. During installation of a
NonStop NS2200 system or HP UPS, your service provider can refer to the "Setting the Ride-Through
Time and Configuring for Maximized Runtime" procedure in the NonStop NS2200 Hardware
Installation Manual for these instructions.
NonStop NS2200 systems require one of the following to support system operation through power
transients or an orderly shutdown of I/O operations and processors during a power failure:
• The optional, HP-supported single-phase UPS (with one to two ERMs for additional battery
runtime) or the HP-supported model R12000/3 three-phase UPS (with one to four ERMs for
additional battery runtime)
• A user-supplied UPS installed in each modular cabinet
• A user-supplied site UPS
If the HP R5000, R5500 XR, or HP R12000/3 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.
When properly configured, OSM power-failure support for NonStop NS2200 systems includes:
• Detection and notification of power failure situations
• Monitoring the outage against a configurable ride-through time in order to avoid disruption
if the power failure is short in duration
• If the ride-through time expires before the power returns, initiating a controlled shutdown of
I/O operations and processors. (This shutdown does not include stopping or powering off the
system, nor does it stop TMF or other applications. Customers are encouraged to execute
scripts to shut down database activity before the processors are shut down.)
You must perform these actions in the OSM Service Connection:
• Perform the Configure a Power Source as UPS action to configure the power rail (either A or
B) connected to the UPS.
• Perform the Configure a Power Source as AC action, to configure the power rail (either B or
A) connected to AC power.
• Perform the Verify Power Fail Configuration, located under the System object, to verify that
power failure support has been properly configured and is in place for the system.
NOTE: For NonStop NS2200 systems, these actions are located under the Power Supply units
located in the VIO modules.
How OSM Power Failure Support Works
NOTE: OSM power failure support works as described only after it has been properly configured.
When OSM detects that one power rail is running on UPS and the other power rail has lost power,
it logs an event indicating the beginning of the configured ride-through time period. OSM monitors
whether AC power returns before the ride-through period ends, and:
• If AC power is restored before the ride-through period ends, the ride-through countdown
terminates and OSM does not take further steps to prepare for an outage.
• If AC power is not restored before the ride-through period ends, OSM broadcasts a
PFAIL_SHOUT message to all processors (the processor running OSM being the last one in
the queue) to shut down the system's ServerNet routers and processors in a fashion designed
to allow disk writes for items that are in transit through controllers and disks to complete.
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