NonStop Operations Guide for H-Series and J-Series RVUs

Power Failure Recovery

After a power failure, if AC power is restored to a NonStop system while the batteries are still

holding up the system, it will not be necessary to restart the system.

Depending on the configuration of UPS resources, power failure can last long enough to leave the

system with some processors down because the batteries were drained to the point where the

processors can no longer operate. In conjunction with an internal UPS, a homogeneous power off

can be configured to avoid this condition.

If the power failure lasts long enough to drain the batteries completely, the system Power/Fail

should stop the system. When power is restored, the operator must then restart the system. Powering

on a CLIM in a NonStop BladeSystem should automatically restart it and the CIP subsystem.

Procedure to Recover From a Power Failure

After power is restored:

1. Power on the system using OSM LLL described in “Powering On a System ” (page 176).

2. Log on to the OSM Service Connection and check the status of all system components to make

sure they are started.

3. Use SCF commands to check the status of external devices and, if necessary, to restart any

external devices to bring them back online.

Setting System Time

Setting the system time is not normally required following a power failure. System time is maintained

by a time-of-day battery in the p-switch, IOAM, or VIO logic board (or by a supercapacitor in the

ServerNet switch in a c7000 enclosure in a NonStop BladeSystem) that is not affected by a power

outage. If required, however, you can set the system time, either programmatically or by using the

TACL command interpreter. Refer to the Guardian Procedure Calls Reference Manual or the TACL

Reference Manual.