System Power-On Methods - IBM S85 pSeries 680 Service Manual

System Power-On Methods

This section discusses the following system power-on methods:
v Power-on Switch - see "Powering On the System" on page 493.
v Remote Power-on via Ring-Indicate Signal
The server automatically powers on when it detects a "ring indicate" signal from a
modem attached to one of the integrated serial ports.
A remote user can call the server to activate ring detection by the modem. Listen for
a few more rings than the threshold number for starting the system and then hang
up. The default threshold is one ring.
Wait five minutes for the server to initialize and then call again using an ASCII
terminal. The server responds by requesting a password, if set, or presenting the
service processor menus. The remote user now has control of the server.
Note: For security, if the system is powered on by the remote power-on via ring
v Unattended start mode - refer to Enable/Disable Unattended Start Mode on page
456.
The service processor can be enabled to recover from the loss of ac power (see
Enable/Disable Unattended Power-On Mode in the SYSTEM POWER CONTROL
MENU). When ac power is restored, the system returns to the then current power
state at the time ac loss occurred. For example, if the system was powered on when
ac loss occurred, it reboots/restarts when power is restored. If the system was
powered off when ac loss occurred, it remains off when power is restored.
It is recommended that the system rack and I/O rack both receive their ac power
from the same building circuit on the same circuit breaker, if not the same electrical
outlet box, in such a way that primary power cannot be lost to one rack separately
from the other. If such a condition occurs, Unattended Start Mode may not be able to
restart system operation when a primary power interruption is restored.
v Timed power-on - refer to the shutdown -t command on servers using AIX.
Working in conjunction with AIX, the service processor in your server can operate a
timer, much like the wake-up timer on your clock radio. You can set the timer so that
your server powers on at a certain time after shutting down. The timer is battery
operated, so power interruptions that occur while the server is off do not affect its
accuracy.
Note: If an ac power loss is in progress when the timed power-on attempt occurs,
v Follow-up to a Failed Boot Attempt
The service processor initiates a power-on sequence upon detection of a failed boot
attempt (due to a hardware or software failure).
v Fast/Slow Boot (IPL) Capabilities
470
Service Guide
indicate signal and the service processor detects an operator panel battery
failure, the service processor causes the system to power off. See "Service
Processor Call-In Security" on page 471 for more information.
the server may not be able to power on when ac power is restored.