Home lab: the server

A Dell PowerEdge R900

Xavier Briand
My journey into Cybersecurity
3 min readMar 6, 2019

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Got a used Dell PowerEdge R900 for $300. This beast comes with:

  • 4 Intel Xeon E7440 Quad Core 2.40Ghz with Intel virtualisation technology (VT-x)
  • 64Go RAM
  • 4 150Go 15K SAS hard drives

That makes it a good enough platform to build a virtual lab.

Dell PowerEdge R900

For the little story, R900 actually means something:

  • R means Rack-mountable server
  • 9 means 4 processors
  • 0 means 10th generation
  • 0 menas Intel CPUs

Cheap and powerful, but big and heavy, not your average tower.

Freaking loud fans

An other problem is the noise level that thing produces.

It mounts four 120x120 fan upfront and has slots for 4 smaller fans at the back.

Popping out 2 fans already made the noise level more bearable, but this was not a sustainable solution.

Research on the Internet yield several results all related to BMC and IPMI, and being able to remotely change the fan speeds.

Setting up IPMI

On the server (Debian):

> apt-get install ipmitool> ipmitool lan set 1 ipaddr [ip address]
> ipmitool lan set 1 defgw ipaddr [gateway ip address]
> ipmitool lan set 1 netmask [mask]
> ipmitool lan set 1 access on
> ipmitool user set password 2 [password]

One the client:

> ipmitool -H [ip address] -U root -p [password] -I lan [command]> ipmitool [...] sensor reading 'FAN 3 RPM' 'FAN 4 RPM'

But:

> ipmitool [...] sensor thresh 'FAN 3 RPM' lcr 2000
Locating sensor record 'FAN 3 RPM'...
Setting sensor "FAN 3 RPM" Lower Critical threshold to 2000.000
Error setting threshold: Command illegal for specified sensor or record type

After a bit of browsing, it appears that the BMC firmware prevent threshold value update.

Replacing the fans

Next, replacing those fans. There is lots of website and video explaining how to replace Dell server fans.

I ordered the new fans, pull out my soldering tools and switched two fans. And oh was I surprised: it went from airport noise level to “Hey, I can hear the hard drives!”.

Fans now spin at 1500 rpm, which apparently could be an issue, their lower threshold being set at 1200 rpm. So far no problems.

If it becomes a problem:

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Xavier Briand
My journey into Cybersecurity

Design & manage software, services, roles, organisations, cultures, games, and my garden.