Homelab: Shushing a loud Dell Server.

/ Christopher Paquin

Rack mount servers are notoriously loud. They are designed to run in data centers which and not next to your head. In a data center no one really notices or cares if a machine’s fans are spinning faster than they need to. 2RU Servers are bad, but 1U are even worse as the smaller the fan the faster they need to spin to move air. Start plugging certified PCI cards into slots and things only get worse. This is exactly my experience with 2 nvidia Tesla T4s in my “used-to-be” quiet Dell T620 (Idrac 7)

Note: Passing fan overrides to the idrac does not survive a reboot/restart and fans won’t spint up if temps rise. See https://github.com/christopherpaquin/Dell-Server-Fan-Shusher for a better solution (GPU aware).

So lets learn to control the noise a bit.

First off you need to enable IPMI over Idrac. In Idrac7 (and Idrac8), log into the web interface, and navigate to IDRAC Settings > Network. Scroll down to IPMI Settings, and make sure that “Enable IPMI Over LAN” is checked. This will allow you to ssh to the idrac and run IPMI commands.

Installing IPMI tool

You will first need to install ipmitool on your workstation. 

$ apt install ipmitool -y

Manual Fan Control

Run the command below to turn on manual control over the fans. You need to do this before you can change their speeds.

ipmitool -I lanplus -H $IP -U $USER -P $PASS raw 0x30 0x30 0x01 0x00

If you want to turn off manual control, and return to auto control, you can run the command below

ipmitool -I lanplus -H $IP -U $USER -P $PASS raw 0x30 0x30 0x01 0x01

Finding your Fans

Run the command below to find our how may system fans you have as well as their numbering

$ ipmitool -I lanplus -H 10.1.10.13 -U root -P calvin sdr list | grep Fan
Fan1             | 1440 RPM          | ok
Fan2             | 1200 RPM          | ok
Fan3             | disabled          | ns
Fan4             | disabled          | ns
Fan5             | disabled          | ns
Fan6             | disabled          | ns
Fan Redundancy   | Not Readable      | ns

Run the command below to set all fans at 40% speed.

  1. 0xff is all fans,
  2. 0x26 is approx 40% (scale is from 0 to 64)
$ ipmitool -I lanplus -H $IP -U $USER -P $PASS raw 0x30 0x30 0x02 0xff 0x26

Check the results.

$ ipmitool -I lanplus -H 10.1.10.13 -U root -P calvin sdr list | egrep -i fan[1,2]
Fan1             | 2400 RPM          | ok
Fan2             | 2040 RPM          | ok

You can also target individual fans. In the example below we will increase fan1 to 100%. Where…

  1. 0x02 is fan1
  2. 0x64 is 100%
$  ipmitool -I lanplus -H 10.1.10.13 -U root -P calvin raw 0x30 0x30 0x02 0x01 0x64

Lets do the same for fan1 (0x00 is fan1)

$ ipmitool -I lanplus -H 10.1.10.13 -U root -P calvin raw 0x30 0x30 0x02 0x00 0x64

Now lets bring both fans back to about 40%

The one-liner below will show you temps as you want to make sure nothing gets too hot. 

$ ipmitool -I lanplus -H 10.1.10.13 -U root -P calvin sdr list | grep Temp
Inlet Temp       | 20 degrees C      | ok
Temp             | 30 degrees C      | ok
Temp             | 25 degrees C      | ok

Additional Tools

Here are a few tools that I have found in my travels

  1. Dell IDRAC Fan Controller Docker – is a docker container that allows you to control fan speeds. Have not tried it but looks pretty simple to use.
  2. R710 Fan Control
  3. Fan Control and Monitoring Script
  4. IDRAC Fan Control
  5. Server Manager

Leave a Reply