Hot Plug Power Supplies; Hot Plug Fans - IBM pSeries 610 model 6C1 Technical Overview And Introduction

Serial port snoop
You can use the serial port snooping at any point after the system is booted to AIX, whenever
the configured reset string is typed on the main console. The system uses the service
processor reboot policy to restart. This action causes an early power off warning (EPOW) to
be logged, and also an AIX dump to be created if the machine is at an AIX prompt, with AIX in
such a state that it can respond. If AIX cannot respond, the EPOW record is created, rather
than the AIX dump.
This functionality is very useful in the unlikely event of a system hang and you have to
administer a remote server.

3.2.3 Hot plug power supplies

The Models 6C1 and 6E1 adopted Netfinity® 5600 power supplies, which consist of up to
three 250 W units. One system unit requires a minimum of two power supplies for normal
operation. To make your system more reliable, you can hot-plug a third power supply for
redundancy. The third power supply is recognized by your system as soon as you plug it in.
With three supplies, if one supply fails, you can do a hot-plug replacement without a
shutdown of your system.
In the unlikely event of one failing power supply (without having the third power supply
installed) or two failing power supplies (if you have installed the redundant power supply), a
system shutdown will be initiated by the operating system.

3.2.4 Hot plug fans

There are four fans in the Models 6C1 and 6E1. All four fans are hot pluggable. Each fan has
a LED to indicate the state of the fan. The Light Path summary panel also has a status LED
for each fan. Off means normal operation and solid-on means fault.
At power on, in order to maintain a low acoustic level, the speed of the fans is ramped up
slowly. The supply voltage of fan 1 and fan 2 is linearly increased from 0V to approximately
6.5V whereas the supply voltage of fan 3 and fan 4 is linearly increased from 0V to
approximately 7.5V. All fans will have their LED (both FRU LED and summary panel fan LED)
turned off (normal operation) when running. As ambient temperature exceeds 24C, the fan
voltage starts increasing linearly, finally reaching its maximum of approximately 12V at 32C.
If one of the four fans fails, the three remaining fans will be placed in the turbo mode (full
speed) by setting the fan supply voltage to 12V. The failing fan LED (both FRU LED and
summary panel fan LED) must be switched to solid-on state indicating a fault condition. An
alert will be send to the operating system that redundant cooling has been lost and a service
call is needed. The failing fan can be replaced (hot-pluggable) while the system is running.
When the failing fan has been replaced and service processor has determined that the new
fan operates properly, the fan LED will be switched to off (normal) via the AIX Service Aid
menu and the fan supply voltages will be returned to nominal level.
If one fan fails and a second fan runs slow or fails, a system shutdown will be issued to the
operating system.
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pSeries 610 Models 6C1 and 6E1 Technical Overview and Introduction