IBM s-series, Инструкция по установке и эксплуатации, Страница: 50 / 170

After a power loss, if the system is left with less than the minimum number of power
supplies required for normal operation, the system will be left in an unknown state.
At this point, manual recovery is required (restore power and power-cycle the
chassis).
Cooling system
The cooling system is contained within the system’s fan tray assembly and
modules. The following components comprise the cooling system:
v The B08S each has six fans.
v
The fans operate at four speeds.
v The B16S has two five-speed fans in the rear of the chassis.
v One fan control module. The fan control module maintains the power to the fans,
and controls the fan speed and the reporting of the fan status to the
management module.
v
Two temperature sensors on each management module, and one temperature
sensor on each interface module
v One temperature sensor on each switch fabric module (B08S and B16S only).
The fan tray in the B08S is located in the right side of each chassis. The B16S has
two fan trays which are located in the top rear of the chassis.
Upon system startup, the fans operate at low speed, then adjust their speed based
on the current temperature of the modules and the configured temperature
thresholds, or by the manually configured fan speed.
By default, the system polls the temperature sensor on each module every 60
seconds to get a temperature reading. To read additional information about
changing the default temperature polling interval, see “Changing the temperature
polling interval” on page 68. Depending on the temperature readings for the
modules, the system can do the following:
v Leave the fan speed at its current setting.
v
Increase the fan speed.
v Decrease the fan speed.
v If the chassis exceeds the highest temperature threshold or shutdown
temperature for five minutes, the system will shut down the device to prevent
damage
If the temperature of a module exceeds specified high temperature thresholds, the
system generates a Syslog message. The system can also power down the chassis
if the temperature exceeds the highest threshold.
You can change default low and high temperature thresholds for modules and fan
speeds. For more information, see “Changing temperature thresholds for thermal
planes and fan speeds on the on the B16S” on page 62.
The chassis ships with all fan components fully installed in the fan tray. To read
additional information about replacing the fan tray, see one of the following sections:
v “Replacing the B08S fan tray” on page 116
v “Replacing the B16S fan assemblies” on page 117
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Ethernet Switch s-series Installation and User Guide