The Thing About Ipmi

You might read my blog post about my CPU running to hot or not then you can do that here.

This incident lead me to investigate the capabilities of my IPMI a bit more. The Intelligent Platform Management Interface or for short IPMI is the interface to your BMC. BMC is the baseboard management controller which is a scary computer in your computer running a network stack and interface directly with your hardware. In general I think it is a good idea to keep that stuff in a very protected network segment.

My main interest was to play around with the cooling fan RPM. Where I didn't really succeeded. But regardless of that here are two of the things I learn in the process. I used a MBD-X10SDV-6C-TLN4F-O Mainboard and installed the ipmitool package on FreeBSD.

Reset user password

The first thing is I set a password and apparently I typed it wrong twice. Not sure how that can happen but it did. And here is how to undo that:

sudo ipmitool user list
sudo ipmitool user set password 3 PASSWORD

List the users and set an new password. (In this case the new password would be PASSWORD) In my case the user had the id 3.

Reboot BMC

And the second thing I learned how to reboot the BMC independent from the computer itself. The issue I had was that a fan failure (me short circuiting the pwm pin of a fan) put all other fans to 100%. Turns out, this is annoyingly loud. As we learned in the intro the BMC is just a computer, meaning we can reboot just like a computer (interdependently for the server).

sudo ipmitool mc reset warm

The important bit here is warm. If you use cold it would restart your server as well.


Here are a few resource in no particular order I consulted.