NonStop NS-Series Planning Guide (H06.04+)

Table Of Contents
Control, Configuration, and Maintenance Tools
HP Integrity NonStop NS-Series Planning Guide529567-005
B-22
AC Power Monitoring
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
shut-down 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 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 modular 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 come from 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.