Users Guide

To set up the properties of fans by using RACADM commands, type the following command at the CLI interface.
racadm fanoffset [-s <off|low|medium|high>]
For more information about the RACADM commands, see the Chassis Management Controller for PowerEdge VRTX RACADM
Command Line Reference Guide available at dell.com/cmcmanuals.
NOTE: The CMC monitors the temperature sensors in the chassis and automatically adjust the fan speed as needed.
However, you can override to maintain a minimum fan speed by the racadm fanoffset command. When overriden using this
command, the CMC will always run the fan to the selected speed even though the chassis does not require the fans to run
at that speed.
CMC generates an alert and increases the fan speeds when the following events occur:
● CMC ambient temperature threshold is exceeded.
● A fan stops functioning.
● A fan is removed from the chassis.
NOTE: During updates of CMC or iDRAC firmware on a server, some or all of the fan units in the chassis rotates at 100%.
This is normal.
To view the health status of fans, in the CMC Web interface, do any of the following:
1. Go to Chassis Overview.
The Chassis Health page is displayed. The lower section of chassis graphics provides the left view of the chassis and
contains the health status of the fans. Fan health status is indicated by the overlay of the fan sub-graphic. Move the cursor
over the fan sub-graphic. The text hint provides additional information about a fan. Click the fan subgraphic to view the fan
information in the right pane.
2. Go to Chassis Overview > Fans.
The Fans Status page provides the status, speed measurements in revolutions per minute (RPMs), and threshold values of
the fans in the chassis. There can be one or more fans.
NOTE:
In the event of a communication failure between CMC and the fan unit, CMC cannot obtain or display the health
status for the fan unit.
NOTE: The following message is displayed when both the fans are not present in the slots or if a fan is rotating at a low
speed:
Fan <number> is less than the lower critical threshold.
For more information, see the Online Help.
Configuring Fans
Fan Offset — A feature to provide increased cooling to the storage and PCIe regions of the chassis. This feature allows you
to increase the airflow delivery to the HDDs, Shared PERC controllers, and PCIe card slots. An example usage of the Fan Offset
is when you use high-power or custom PCIe cards that require more cooling than normal. The Fan Offset feature has options
of Off, Low, Medium, and High. These settings correspond to a fan speed offset (increase) of 20%, 50%, and 100% of the
maximum speed respectively. There are also minimum speeds setup for each option, which are 35% for Low, 65% for Medium,
and 100% for High.
Using the Medium Fan Offset setting for example, increases the speed of fans 1–6 by 50% of its maximum speed. The increase
is above the speed already set by the system for cooling on the basis of installed hardware configuration.
With any of the Fan Offset options enabled, the power consumption will be increased. The system will be louder with the Low
offset, noticeably louder with the Medium offset, and significantly louder with the High offset. When the Fan Offset option
is not enabled, the fan speeds will be reduced to the default speeds required for system cooling for the installed hardware
configuration.
To set the offset feature, go to Chassis Overview > Fans > Setup. On the Advanced Fan Configurations page, in the Fan
Configuration table, from the Value drop-down menu corresponding to Fan Offset, select an option appropriately.
For more information about the Fan Offset feature, see the Online Help.
For setting up these features by using RACADM commands, user the following command:
racadm fanoffset [-s <off|low|medium|high>]
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Viewing Chassis Information and Monitoring Chassis and Component Health