Installation guide

Dealing with Power Failures
HP-UX version 11.00.03 Starting and Stopping the System 3-29
Dealing with Power Failures
Continuum systems provide power failure protection when connected to an
approved UPS through the console controller’s auxiliary port (configured to
support a UPS). If an external power failure occurs, the UPS notifies the system of
the power failure and switches to battery power.
When the system receives the power failure report from the UPS, it waits for the
specified grace period. The system continues to function normally during the
grace period. If power is restored during the grace period, normal system
operation continues. If power is not restored during the grace period, the system
performs an orderly shutdown. The grace period is 60 seconds by default, but you
can customize the powerdown grace period to suit your environment.
You can also adjust several other parameters to control the usage of the batteries.
This is intended for use with a UPS where the type of battery is not known.
The parameters available are:
■ grace period
■ discharge seconds
■ maximum ridethrough seconds
■ battery factor
■ shutdown time
Information on the grace period is provided below. The other parameters are set
by including them on the command line defined in the inittab file, as shown in
the grace period example. See the powerdown(1M) man page for details on the
parameters.
CAUTION
A Continuum Series 400 system immediately halts when power fails if
it is not connected to a UPS; it does not have time to perform any
shutdown procedures.
If you do not have a UPS on a Continuum Series 400 system to give your system
time to shut down gracefully in the event of a power failure, your recovery
procedure is very limited. You must simply reboot the system and verify that your
file systems were not corrupted. Contact the CAC for further assistance.